Paper Plugins

Co-authored-by: Micah Rao <micah.s.rao@gmail.com>

paper-server/patches/sources/net/minecraft/core/registries/BuiltInRegistries.java.patch

@@ -1,6 +1,6 @@
 --- a/net/minecraft/core/registries/BuiltInRegistries.java
 +++ b/net/minecraft/core/registries/BuiltInRegistries.java
-@@ -325,7 +325,7 @@
+@@ -325,12 +325,18 @@
          Bootstrap.checkBootstrapCalled(() -> "registry " + key.location());
          ResourceLocation resourceLocation = key.location();
          LOADERS.put(resourceLocation, () -> initializer.run(registry));
@@ -9,3 +9,14 @@
          return registry;
      }
  
+     public static void bootStrap() {
++        // Paper start
++        bootStrap(() -> {});
++    }
++    public static void bootStrap(Runnable runnable) {
++        // Paper end
+         createContents();
++        runnable.run(); // Paper
+         freeze();
+         validate(REGISTRY);
+     }

paper-server/patches/sources/net/minecraft/server/Bootstrap.java.patch

@@ -20,7 +20,7 @@
  public class Bootstrap {
  
      public static final PrintStream STDOUT = System.out;
-@@ -42,6 +46,23 @@
+@@ -42,9 +46,27 @@
  
      public static void bootStrap() {
          if (!Bootstrap.isBootstrapped) {
@@ -44,7 +44,20 @@
              Bootstrap.isBootstrapped = true;
              Instant instant = Instant.now();
  
-@@ -61,6 +82,69 @@
++            io.papermc.paper.plugin.entrypoint.LaunchEntryPointHandler.enterBootstrappers(); // Paper - Entrypoint for bootstrapping
+             if (BuiltInRegistries.REGISTRY.keySet().isEmpty()) {
+                 throw new IllegalStateException("Unable to load registries");
+             } else {
+@@ -56,11 +78,77 @@
+                     EntitySelectorOptions.bootStrap();
+                     DispenseItemBehavior.bootStrap();
+                     CauldronInteraction.bootStrap();
+-                    BuiltInRegistries.bootStrap();
++                    // Paper start
++                    BuiltInRegistries.bootStrap(() -> {
++                    });
++                    // Paper end
+                     CreativeModeTabs.validate();
                      Bootstrap.wrapStreams();
                      Bootstrap.bootstrapDuration.set(Duration.between(instant, Instant.now()).toMillis());
                  }

paper-server/patches/sources/net/minecraft/server/Main.java.patch

@@ -43,7 +43,7 @@
          OptionParser optionparser = new OptionParser();
          OptionSpec<Void> optionspec = optionparser.accepts("nogui");
          OptionSpec<Void> optionspec1 = optionparser.accepts("initSettings", "Initializes 'server.properties' and 'eula.txt', then quits");
-@@ -90,21 +100,24 @@
+@@ -90,50 +100,82 @@
          OptionSpec<String> optionspec15 = optionparser.nonOptions();
  
          try {
@@ -71,7 +71,8 @@
                  JvmProfiler.INSTANCE.start(Environment.SERVER);
              }
  
-@@ -112,28 +125,56 @@
++            io.papermc.paper.plugin.PluginInitializerManager.load(optionset); // Paper
+             Bootstrap.bootStrap();
              Bootstrap.validate();
              Util.startTimerHackThread();
              Path path1 = Paths.get("server.properties");
@@ -135,7 +136,7 @@
              Dynamic dynamic;
  
              if (convertable_conversionsession.hasWorldData()) {
-@@ -174,13 +215,31 @@
+@@ -174,13 +216,31 @@
              }
  
              Dynamic<?> dynamic1 = dynamic;
@@ -168,7 +169,7 @@
  
              WorldStem worldstem;
  
-@@ -189,6 +248,7 @@
+@@ -189,6 +249,7 @@
  
                  worldstem = (WorldStem) Util.blockUntilDone((executor) -> {
                      return WorldLoader.load(worldloader_c, (worldloader_a) -> {
@@ -176,7 +177,7 @@
                          Registry<LevelStem> iregistry = worldloader_a.datapackDimensions().lookupOrThrow(Registries.LEVEL_STEM);
  
                          if (dynamic1 != null) {
-@@ -201,7 +261,7 @@
+@@ -201,7 +262,7 @@
                              WorldOptions worldoptions;
                              WorldDimensions worlddimensions;
  
@@ -185,7 +186,7 @@
                                  worldsettings = MinecraftServer.DEMO_SETTINGS;
                                  worldoptions = WorldOptions.DEMO_OPTIONS;
                                  worlddimensions = WorldPresets.createNormalWorldDimensions(worldloader_a.datapackWorldgen());
-@@ -209,7 +269,7 @@
+@@ -209,7 +270,7 @@
                                  DedicatedServerProperties dedicatedserverproperties = dedicatedserversettings.getProperties();
  
                                  worldsettings = new LevelSettings(dedicatedserverproperties.levelName, dedicatedserverproperties.gamemode, dedicatedserverproperties.hardcore, dedicatedserverproperties.difficulty, false, new GameRules(worldloader_a.dataConfiguration().enabledFeatures()), worldloader_a.dataConfiguration());
@@ -194,7 +195,7 @@
                                  worlddimensions = dedicatedserverproperties.createDimensions(worldloader_a.datapackWorldgen());
                              }
  
-@@ -225,32 +285,44 @@
+@@ -225,32 +286,44 @@
                  return;
              }
  
@@ -244,7 +245,7 @@
              Thread thread = new Thread("Server Shutdown Thread") {
                  public void run() {
                      dedicatedserver.halt(true);
-@@ -259,6 +331,7 @@
+@@ -259,6 +332,7 @@
  
              thread.setUncaughtExceptionHandler(new DefaultUncaughtExceptionHandler(Main.LOGGER));
              Runtime.getRuntime().addShutdownHook(thread);
@@ -252,7 +253,7 @@
          } catch (Exception exception1) {
              Main.LOGGER.error(LogUtils.FATAL_MARKER, "Failed to start the minecraft server", exception1);
          }
-@@ -295,7 +368,7 @@
+@@ -295,7 +369,7 @@
      }
  
      public static void forceUpgrade(LevelStorageSource.LevelStorageAccess session, DataFixer dataFixer, boolean eraseCache, BooleanSupplier continueCheck, RegistryAccess dynamicRegistryManager, boolean recreateRegionFiles) {

paper-server/src/main/java/io/papermc/paper/command/PaperCommand.java

@@ -37,6 +37,7 @@ public final class PaperCommand extends Command {
         commands.put(Set.of("entity"), new EntityCommand());
         commands.put(Set.of("reload"), new ReloadCommand());
         commands.put(Set.of("version"), new VersionCommand());
+        commands.put(Set.of("dumpplugins"), new DumpPluginsCommand());
 
         return commands.entrySet().stream()
             .flatMap(entry -> entry.getKey().stream().map(s -> Map.entry(s, entry.getValue())))

paper-server/src/main/java/io/papermc/paper/command/PaperCommands.java

@@ -24,5 +24,6 @@ public final class PaperCommands {
         COMMANDS.forEach((s, command) -> {
             server.server.getCommandMap().register(s, "Paper", command);
         });
+        server.server.getCommandMap().register("bukkit", new PaperPluginsCommand());
     }
 }

paper-server/src/main/java/io/papermc/paper/command/PaperPluginsCommand.java

@@ -0,0 +1,215 @@
+package io.papermc.paper.command;
+
+import com.google.common.collect.Lists;
+import io.leangen.geantyref.GenericTypeReflector;
+import io.leangen.geantyref.TypeToken;
+import io.papermc.paper.plugin.configuration.PluginMeta;
+import io.papermc.paper.plugin.entrypoint.Entrypoint;
+import io.papermc.paper.plugin.entrypoint.LaunchEntryPointHandler;
+import io.papermc.paper.plugin.provider.PluginProvider;
+import io.papermc.paper.plugin.provider.ProviderStatus;
+import io.papermc.paper.plugin.provider.ProviderStatusHolder;
+import io.papermc.paper.plugin.provider.type.paper.PaperPluginParent;
+import io.papermc.paper.plugin.provider.type.spigot.SpigotPluginProvider;
+import net.kyori.adventure.text.Component;
+import net.kyori.adventure.text.JoinConfiguration;
+import net.kyori.adventure.text.TextComponent;
+import net.kyori.adventure.text.event.ClickEvent;
+import net.kyori.adventure.text.format.NamedTextColor;
+import net.kyori.adventure.text.format.TextColor;
+import org.bukkit.Bukkit;
+import org.bukkit.command.CommandSender;
+import org.bukkit.command.defaults.BukkitCommand;
+import org.bukkit.craftbukkit.util.CraftMagicNumbers;
+import org.bukkit.plugin.Plugin;
+import org.bukkit.plugin.java.JavaPlugin;
+import org.jetbrains.annotations.NotNull;
+
+import java.lang.reflect.Type;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Collections;
+import java.util.List;
+import java.util.TreeMap;
+
+public class PaperPluginsCommand extends BukkitCommand {
+
+    private static final TextColor INFO_COLOR = TextColor.color(52, 159, 218);
+
+    // TODO: LINK?
+    private static final Component SERVER_PLUGIN_INFO = Component.text("ℹ What is a server plugin?", INFO_COLOR)
+        .append(asPlainComponents("""
+            Server plugins can add new behavior to your server!
+            You can find new plugins on Paper's plugin repository, Hangar.
+                        
+            <link to hangar>
+            """));
+
+    private static final Component SERVER_INITIALIZER_INFO = Component.text("ℹ What is a server initializer?", INFO_COLOR)
+        .append(asPlainComponents("""
+            Server initializers are ran before your server
+            starts and are provided by paper plugins.
+            """));
+
+    private static final Component LEGACY_PLUGIN_INFO = Component.text("ℹ What is a legacy plugin?", INFO_COLOR)
+        .append(asPlainComponents("""
+            A legacy plugin is a plugin that was made on
+            very old unsupported versions of the game.
+                        
+            It is encouraged that you replace this plugin,
+            as they might not work in the future and may cause
+            performance issues.
+            """));
+
+    private static final Component LEGACY_PLUGIN_STAR = Component.text('*', TextColor.color(255, 212, 42)).hoverEvent(LEGACY_PLUGIN_INFO);
+    private static final Component INFO_ICON_START = Component.text("ℹ ", INFO_COLOR);
+    private static final Component PAPER_HEADER = Component.text("Paper Plugins:", TextColor.color(2, 136, 209));
+    private static final Component BUKKIT_HEADER = Component.text("Bukkit Plugins:", TextColor.color(237, 129, 6));
+    private static final Component PLUGIN_TICK = Component.text("- ", NamedTextColor.DARK_GRAY);
+    private static final Component PLUGIN_TICK_EMPTY = Component.text(" ");
+
+    private static final Type JAVA_PLUGIN_PROVIDER_TYPE = new TypeToken<PluginProvider<JavaPlugin>>() {}.getType();
+
+    public PaperPluginsCommand() {
+        super("plugins");
+        this.description = "Gets a list of plugins running on the server";
+        this.usageMessage = "/plugins";
+        this.setPermission("bukkit.command.plugins");
+        this.setAliases(Arrays.asList("pl"));
+    }
+
+    private static <T> List<Component> formatProviders(TreeMap<String, PluginProvider<T>> plugins) {
+        List<Component> components = new ArrayList<>(plugins.size());
+        for (PluginProvider<T> entry : plugins.values()) {
+            components.add(formatProvider(entry));
+        }
+
+        boolean isFirst = true;
+        List<Component> formattedSublists = new ArrayList<>();
+        /*
+        Split up the plugin list for each 10 plugins to get size down
+
+        Plugin List:
+        - Plugin 1, Plugin 2, .... Plugin 10,
+          Plugin 11, Plugin 12 ... Plugin 20,
+         */
+        for (List<Component> componentSublist : Lists.partition(components, 10)) {
+            Component component = Component.space();
+            if (isFirst) {
+                component = component.append(PLUGIN_TICK);
+                isFirst = false;
+            } else {
+                component = PLUGIN_TICK_EMPTY;
+                //formattedSublists.add(Component.empty()); // Add an empty line, the auto chat wrapping and this makes it quite jarring.
+            }
+
+            formattedSublists.add(component.append(Component.join(JoinConfiguration.commas(true), componentSublist)));
+        }
+
+        return formattedSublists;
+    }
+
+    private static Component formatProvider(PluginProvider<?> provider) {
+        TextComponent.Builder builder = Component.text();
+        if (provider instanceof SpigotPluginProvider spigotPluginProvider && CraftMagicNumbers.isLegacy(spigotPluginProvider.getMeta())) {
+            builder.append(LEGACY_PLUGIN_STAR);
+        }
+
+        String name = provider.getMeta().getName();
+        Component pluginName = Component.text(name, fromStatus(provider))
+            .clickEvent(ClickEvent.runCommand("/version " + name));
+
+        builder.append(pluginName);
+
+        return builder.build();
+    }
+
+    private static Component asPlainComponents(String strings) {
+        net.kyori.adventure.text.TextComponent.Builder builder = Component.text();
+        for (String string : strings.split("\n")) {
+            builder.append(Component.newline());
+            builder.append(Component.text(string, NamedTextColor.WHITE));
+        }
+
+        return builder.build();
+    }
+
+    private static TextColor fromStatus(PluginProvider<?> provider) {
+        if (provider instanceof ProviderStatusHolder statusHolder && statusHolder.getLastProvidedStatus() != null) {
+            ProviderStatus status = statusHolder.getLastProvidedStatus();
+
+            // Handle enabled/disabled game plugins
+            if (status == ProviderStatus.INITIALIZED && GenericTypeReflector.isSuperType(JAVA_PLUGIN_PROVIDER_TYPE, provider.getClass())) {
+                Plugin plugin = Bukkit.getPluginManager().getPlugin(provider.getMeta().getName());
+                // Plugin doesn't exist? Could be due to it being removed.
+                if (plugin == null) {
+                    return NamedTextColor.RED;
+                }
+
+                return plugin.isEnabled() ? NamedTextColor.GREEN : NamedTextColor.RED;
+            }
+
+            return switch (status) {
+                case INITIALIZED -> NamedTextColor.GREEN;
+                case ERRORED -> NamedTextColor.RED;
+            };
+        } else if (provider instanceof PaperPluginParent.PaperServerPluginProvider serverPluginProvider && serverPluginProvider.shouldSkipCreation()) {
+            // Paper plugins will be skipped if their provider is skipped due to their initializer failing.
+            // Show them as red
+            return NamedTextColor.RED;
+        } else {
+            // Separated for future logic choice, but this indicated a provider that failed to load due to
+            // dependency issues or what not.
+            return NamedTextColor.RED;
+        }
+    }
+
+    @Override
+    public boolean execute(@NotNull CommandSender sender, @NotNull String currentAlias, @NotNull String[] args) {
+        if (!this.testPermission(sender)) return true;
+
+        TreeMap<String, PluginProvider<JavaPlugin>> paperPlugins = new TreeMap<>(String.CASE_INSENSITIVE_ORDER);
+        TreeMap<String, PluginProvider<JavaPlugin>> spigotPlugins = new TreeMap<>(String.CASE_INSENSITIVE_ORDER);
+
+
+        for (PluginProvider<JavaPlugin> provider : LaunchEntryPointHandler.INSTANCE.get(Entrypoint.PLUGIN).getRegisteredProviders()) {
+            PluginMeta configuration = provider.getMeta();
+
+            if (provider instanceof SpigotPluginProvider) {
+                spigotPlugins.put(configuration.getDisplayName(), provider);
+            } else if (provider instanceof PaperPluginParent.PaperServerPluginProvider) {
+                paperPlugins.put(configuration.getDisplayName(), provider);
+            }
+        }
+
+        Component infoMessage = Component.text("Server Plugins (%s):".formatted(paperPlugins.size() + spigotPlugins.size()), NamedTextColor.WHITE);
+            //.append(INFO_ICON_START.hoverEvent(SERVER_PLUGIN_INFO)); TODO: Add docs
+
+        sender.sendMessage(infoMessage);
+
+        if (!paperPlugins.isEmpty()) {
+            sender.sendMessage(PAPER_HEADER);
+        }
+
+        for (Component component : formatProviders(paperPlugins)) {
+            sender.sendMessage(component);
+        }
+
+        if (!spigotPlugins.isEmpty()) {
+            sender.sendMessage(BUKKIT_HEADER);
+        }
+        
+        for (Component component : formatProviders(spigotPlugins)) {
+            sender.sendMessage(component);
+        }
+
+        return true;
+    }
+
+    @NotNull
+    @Override
+    public List<String> tabComplete(@NotNull CommandSender sender, @NotNull String alias, @NotNull String[] args) throws IllegalArgumentException {
+        return Collections.emptyList();
+    }
+
+}

paper-server/src/main/java/io/papermc/paper/command/subcommands/DumpPluginsCommand.java

@@ -0,0 +1,203 @@
+package io.papermc.paper.command.subcommands;
+
+import com.google.common.graph.GraphBuilder;
+import com.google.gson.JsonArray;
+import com.google.gson.JsonElement;
+import com.google.gson.JsonObject;
+import com.google.gson.JsonPrimitive;
+import com.google.gson.internal.Streams;
+import com.google.gson.stream.JsonWriter;
+import io.papermc.paper.command.PaperSubcommand;
+import io.papermc.paper.plugin.entrypoint.Entrypoint;
+import io.papermc.paper.plugin.entrypoint.LaunchEntryPointHandler;
+import io.papermc.paper.plugin.entrypoint.classloader.group.LockingClassLoaderGroup;
+import io.papermc.paper.plugin.entrypoint.classloader.group.PaperPluginClassLoaderStorage;
+import io.papermc.paper.plugin.entrypoint.classloader.group.SimpleListPluginClassLoaderGroup;
+import io.papermc.paper.plugin.entrypoint.classloader.group.SpigotPluginClassLoaderGroup;
+import io.papermc.paper.plugin.entrypoint.classloader.group.StaticPluginClassLoaderGroup;
+import io.papermc.paper.plugin.entrypoint.dependency.GraphDependencyContext;
+import io.papermc.paper.plugin.entrypoint.dependency.SimpleMetaDependencyTree;
+import io.papermc.paper.plugin.provider.entrypoint.DependencyContext;
+import io.papermc.paper.plugin.entrypoint.strategy.modern.ModernPluginLoadingStrategy;
+import io.papermc.paper.plugin.entrypoint.strategy.ProviderConfiguration;
+import io.papermc.paper.plugin.manager.PaperPluginManagerImpl;
+import io.papermc.paper.plugin.provider.PluginProvider;
+import io.papermc.paper.plugin.provider.classloader.ConfiguredPluginClassLoader;
+import io.papermc.paper.plugin.provider.classloader.PaperClassLoaderStorage;
+import io.papermc.paper.plugin.provider.classloader.PluginClassLoaderGroup;
+import io.papermc.paper.plugin.storage.ConfiguredProviderStorage;
+import io.papermc.paper.plugin.storage.ProviderStorage;
+import net.minecraft.server.MinecraftServer;
+import org.bukkit.command.CommandSender;
+import org.bukkit.plugin.Plugin;
+import org.checkerframework.checker.nullness.qual.NonNull;
+import org.checkerframework.framework.qual.DefaultQualifier;
+
+import java.io.PrintStream;
+import java.io.StringWriter;
+import java.nio.charset.StandardCharsets;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.time.LocalDateTime;
+import java.time.format.DateTimeFormatter;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Map;
+
+import static net.kyori.adventure.text.Component.text;
+import static net.kyori.adventure.text.format.NamedTextColor.GREEN;
+import static net.kyori.adventure.text.format.NamedTextColor.RED;
+
+@DefaultQualifier(NonNull.class)
+public final class DumpPluginsCommand implements PaperSubcommand {
+    @Override
+    public boolean execute(final CommandSender sender, final String subCommand, final String[] args) {
+        this.dumpPlugins(sender, args);
+        return true;
+    }
+
+    private static final DateTimeFormatter FORMATTER = DateTimeFormatter.ofPattern("yyyy-MM-dd_HH.mm.ss");
+
+    private void dumpPlugins(final CommandSender sender, final String[] args) {
+        Path parent = Path.of("debug");
+        Path path = parent.resolve("plugin-info-" + FORMATTER.format(LocalDateTime.now()) + ".txt");
+        try {
+            Files.createDirectories(parent);
+            Files.createFile(path);
+            sender.sendMessage(text("Writing plugin information to " + path, GREEN));
+
+            final JsonObject data = this.writeDebug();
+
+            StringWriter stringWriter = new StringWriter();
+            JsonWriter jsonWriter = new JsonWriter(stringWriter);
+            jsonWriter.setIndent(" ");
+            jsonWriter.setLenient(false);
+            Streams.write(data, jsonWriter);
+
+            try (PrintStream out = new PrintStream(Files.newOutputStream(path), false, StandardCharsets.UTF_8)) {
+                out.print(stringWriter);
+            }
+            sender.sendMessage(text("Successfully written plugin debug information!", GREEN));
+        } catch (Throwable e) {
+            sender.sendMessage(text("Failed to write plugin information! See the console for more info.", RED));
+            MinecraftServer.LOGGER.warn("Error occurred while dumping plugin info", e);
+        }
+    }
+
+    private JsonObject writeDebug() {
+        JsonObject root = new JsonObject();
+        if (ConfiguredProviderStorage.LEGACY_PLUGIN_LOADING) {
+            root.addProperty("legacy-loading-strategy", true);
+        }
+
+        this.writeProviders(root);
+        this.writePlugins(root);
+        this.writeClassloaders(root);
+
+        return root;
+    }
+
+    private void writeProviders(JsonObject root) {
+        JsonObject rootProviders = new JsonObject();
+        root.add("providers", rootProviders);
+
+        for (Map.Entry<Entrypoint<?>, ProviderStorage<?>> entry : LaunchEntryPointHandler.INSTANCE.getStorage().entrySet()) {
+            JsonObject entrypoint = new JsonObject();
+
+            JsonArray providers = new JsonArray();
+            entrypoint.add("providers", providers);
+
+            List<PluginProvider<Object>> pluginProviders = new ArrayList<>();
+            for (PluginProvider<?> provider : entry.getValue().getRegisteredProviders()) {
+                JsonObject providerObj = new JsonObject();
+                providerObj.addProperty("name", provider.getMeta().getName());
+                providerObj.addProperty("version", provider.getMeta().getVersion());
+                providerObj.addProperty("dependencies", provider.getMeta().getPluginDependencies().toString());
+                providerObj.addProperty("soft-dependencies", provider.getMeta().getPluginSoftDependencies().toString());
+                providerObj.addProperty("load-before", provider.getMeta().getLoadBeforePlugins().toString());
+
+
+                providers.add(providerObj);
+                pluginProviders.add((PluginProvider<Object>) provider);
+            }
+
+            JsonArray loadOrder = new JsonArray();
+            entrypoint.add("load-order", loadOrder);
+
+            ModernPluginLoadingStrategy<Object> modernPluginLoadingStrategy = new ModernPluginLoadingStrategy<>(new ProviderConfiguration<>() {
+                @Override
+                public void applyContext(PluginProvider<Object> provider, DependencyContext dependencyContext) {
+                }
+
+                @Override
+                public boolean load(PluginProvider<Object> provider, Object provided) {
+                    return true;
+                }
+
+                @Override
+                public boolean preloadProvider(PluginProvider<Object> provider) {
+                    // Don't load provider
+                    loadOrder.add(provider.getMeta().getName());
+                    return false;
+                }
+            });
+            modernPluginLoadingStrategy.loadProviders(pluginProviders, new SimpleMetaDependencyTree(GraphBuilder.directed().build()));
+
+            rootProviders.add(entry.getKey().getDebugName(), entrypoint);
+        }
+    }
+
+    private void writePlugins(JsonObject root) {
+        JsonArray rootPlugins = new JsonArray();
+        root.add("plugins", rootPlugins);
+
+        for (Plugin plugin : PaperPluginManagerImpl.getInstance().getPlugins()) {
+            rootPlugins.add(plugin.toString());
+        }
+    }
+
+    private void writeClassloaders(JsonObject root) {
+        JsonObject classLoadersRoot = new JsonObject();
+        root.add("classloaders", classLoadersRoot);
+
+        PaperPluginClassLoaderStorage storage = (PaperPluginClassLoaderStorage) PaperClassLoaderStorage.instance();
+        classLoadersRoot.addProperty("global", storage.getGlobalGroup().toString());
+        classLoadersRoot.addProperty("dependency_graph", PaperPluginManagerImpl.getInstance().getInstanceManagerGraph().toString());
+
+        JsonArray array = new JsonArray();
+        classLoadersRoot.add("children", array);
+        for (PluginClassLoaderGroup group : storage.getGroups()) {
+            array.add(this.writeClassloader(group));
+        }
+    }
+
+    private JsonObject writeClassloader(PluginClassLoaderGroup group) {
+        JsonObject classLoadersRoot = new JsonObject();
+        if (group instanceof SimpleListPluginClassLoaderGroup listGroup) {
+            JsonArray array = new JsonArray();
+            classLoadersRoot.addProperty("main", listGroup.toString());
+            if (group instanceof StaticPluginClassLoaderGroup staticPluginClassLoaderGroup) {
+                classLoadersRoot.addProperty("plugin-holder", staticPluginClassLoaderGroup.getPluginClassloader().toString());
+            } else if (group instanceof SpigotPluginClassLoaderGroup spigotPluginClassLoaderGroup) {
+                classLoadersRoot.addProperty("plugin-holder", spigotPluginClassLoaderGroup.getPluginClassLoader().toString());
+            }
+
+            classLoadersRoot.add("children", array);
+            for (ConfiguredPluginClassLoader innerGroup : listGroup.getClassLoaders()) {
+                array.add(this.writeClassloader(innerGroup));
+            }
+
+        } else if (group instanceof LockingClassLoaderGroup locking) {
+            // Unwrap
+            return this.writeClassloader(locking.getParent());
+        } else {
+            classLoadersRoot.addProperty("raw", group.toString());
+        }
+
+        return classLoadersRoot;
+    }
+
+    private JsonElement writeClassloader(ConfiguredPluginClassLoader innerGroup) {
+        return new JsonPrimitive(innerGroup.toString());
+    }
+}

paper-server/src/main/java/io/papermc/paper/plugin/PluginInitializerManager.java

@@ -0,0 +1,134 @@
+package io.papermc.paper.plugin;
+
+import com.mojang.logging.LogUtils;
+import io.papermc.paper.configuration.PaperConfigurations;
+import io.papermc.paper.plugin.entrypoint.Entrypoint;
+import io.papermc.paper.plugin.entrypoint.LaunchEntryPointHandler;
+import io.papermc.paper.plugin.provider.PluginProvider;
+import io.papermc.paper.plugin.provider.type.paper.PaperPluginParent;
+import joptsimple.OptionSet;
+import net.minecraft.server.dedicated.DedicatedServer;
+import org.bukkit.configuration.file.YamlConfiguration;
+import org.bukkit.craftbukkit.CraftServer;
+import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
+import org.slf4j.Logger;
+
+import java.io.File;
+import java.io.IOException;
+import java.nio.file.Files;
+import java.nio.file.Path;
+
+public class PluginInitializerManager {
+
+    private static final Logger LOGGER = LogUtils.getClassLogger();
+    private static PluginInitializerManager impl;
+    private final Path pluginDirectory;
+    private final Path updateDirectory;
+
+    PluginInitializerManager(final Path pluginDirectory, final Path updateDirectory) {
+        this.pluginDirectory = pluginDirectory;
+        this.updateDirectory = updateDirectory;
+    }
+
+    private static PluginInitializerManager parse(@NotNull final OptionSet minecraftOptionSet) throws Exception {
+        // We have to load the bukkit configuration inorder to get the update folder location.
+        final File configFileLocationBukkit = (File) minecraftOptionSet.valueOf("bukkit-settings");
+
+        final Path pluginDirectory = ((File) minecraftOptionSet.valueOf("plugins")).toPath();
+
+        final YamlConfiguration configuration = PaperConfigurations.loadLegacyConfigFile(configFileLocationBukkit);
+
+        final String updateDirectoryName = configuration.getString("settings.update-folder", "update");
+        if (updateDirectoryName.isBlank()) {
+            return new PluginInitializerManager(pluginDirectory, null);
+        }
+
+        final Path resolvedUpdateDirectory = pluginDirectory.resolve(updateDirectoryName);
+        if (!Files.isDirectory(resolvedUpdateDirectory)) {
+            if (Files.exists(resolvedUpdateDirectory)) {
+                LOGGER.error("Misconfigured update directory!");
+                LOGGER.error("Your configured update directory ({}) in bukkit.yml is pointing to a non-directory path. " +
+                    "Auto updating functionality will not work.", resolvedUpdateDirectory);
+            }
+            return new PluginInitializerManager(pluginDirectory, null);
+        }
+
+        boolean isSameFile;
+        try {
+            isSameFile = Files.isSameFile(resolvedUpdateDirectory, pluginDirectory);
+        } catch (final IOException e) {
+            LOGGER.error("Misconfigured update directory!");
+            LOGGER.error("Failed to compare update/plugin directory", e);
+            return new PluginInitializerManager(pluginDirectory, null);
+        }
+
+        if (isSameFile) {
+            LOGGER.error("Misconfigured update directory!");
+            LOGGER.error(("Your configured update directory (%s) in bukkit.yml is pointing to the same location as the plugin directory (%s). " +
+                "Disabling auto updating functionality.").formatted(resolvedUpdateDirectory, pluginDirectory));
+
+            return new PluginInitializerManager(pluginDirectory, null);
+        }
+
+        return new PluginInitializerManager(pluginDirectory, resolvedUpdateDirectory);
+    }
+
+    public static PluginInitializerManager init(final OptionSet optionSet) throws Exception {
+        impl = parse(optionSet);
+        return impl;
+    }
+
+    public static PluginInitializerManager instance() {
+        return impl;
+    }
+
+    @NotNull
+    public Path pluginDirectoryPath() {
+        return pluginDirectory;
+    }
+
+    @Nullable
+    public Path pluginUpdatePath() {
+        return updateDirectory;
+    }
+
+    public static void load(OptionSet optionSet) throws Exception {
+        // We have to load the bukkit configuration inorder to get the update folder location.
+        io.papermc.paper.plugin.PluginInitializerManager pluginSystem = io.papermc.paper.plugin.PluginInitializerManager.init(optionSet);
+
+        // Register the default plugin directory
+        io.papermc.paper.plugin.util.EntrypointUtil.registerProvidersFromSource(io.papermc.paper.plugin.provider.source.DirectoryProviderSource.INSTANCE, pluginSystem.pluginDirectoryPath());
+
+        // Register plugins from the flag
+        @SuppressWarnings("unchecked")
+        java.util.List<Path> files = ((java.util.List<File>) optionSet.valuesOf("add-plugin")).stream().map(File::toPath).toList();
+        io.papermc.paper.plugin.util.EntrypointUtil.registerProvidersFromSource(io.papermc.paper.plugin.provider.source.PluginFlagProviderSource.INSTANCE, files);
+    }
+
+    // This will be the end of me...
+    public static void reload(DedicatedServer dedicatedServer) {
+        // Wipe the provider storage
+        LaunchEntryPointHandler.INSTANCE.populateProviderStorage();
+        try {
+            load(dedicatedServer.options);
+        } catch (Exception e) {
+            throw new RuntimeException("Failed to reload!", e);
+        }
+
+        boolean hasPaperPlugin = false;
+        for (PluginProvider<?> provider : LaunchEntryPointHandler.INSTANCE.getStorage().get(Entrypoint.PLUGIN).getRegisteredProviders()) {
+            if (provider instanceof PaperPluginParent.PaperServerPluginProvider) {
+                hasPaperPlugin = true;
+                break;
+            }
+        }
+
+        if (hasPaperPlugin) {
+            LOGGER.warn("======== WARNING ========");
+            LOGGER.warn("You are reloading while having Paper plugins installed on your server.");
+            LOGGER.warn("Paper plugins do NOT support being reloaded. This will cause some unexpected issues.");
+            LOGGER.warn("=========================");
+        }
+    }
+}

paper-server/src/main/java/io/papermc/paper/plugin/bootstrap/PluginBootstrapContextImpl.java

@@ -0,0 +1,48 @@
+package io.papermc.paper.plugin.bootstrap;
+
+import io.papermc.paper.plugin.configuration.PluginMeta;
+import io.papermc.paper.plugin.provider.PluginProvider;
+import java.nio.file.Path;
+import net.kyori.adventure.text.logger.slf4j.ComponentLogger;
+import org.jetbrains.annotations.NotNull;
+
+public final class PluginBootstrapContextImpl implements BootstrapContext {
+
+    private final PluginMeta config;
+    private final Path dataFolder;
+    private final ComponentLogger logger;
+    private final Path pluginSource;
+
+    public PluginBootstrapContextImpl(PluginMeta config, Path dataFolder, ComponentLogger logger, Path pluginSource) {
+        this.config = config;
+        this.dataFolder = dataFolder;
+        this.logger = logger;
+        this.pluginSource = pluginSource;
+    }
+
+    public static PluginBootstrapContextImpl create(PluginProvider<?> provider, Path pluginFolder) {
+        Path dataFolder = pluginFolder.resolve(provider.getMeta().getName());
+
+        return new PluginBootstrapContextImpl(provider.getMeta(), dataFolder, provider.getLogger(), provider.getSource());
+    }
+
+    @Override
+    public @NotNull PluginMeta getConfiguration() {
+        return this.config;
+    }
+
+    @Override
+    public @NotNull Path getDataDirectory() {
+        return this.dataFolder;
+    }
+
+    @Override
+    public @NotNull ComponentLogger getLogger() {
+        return this.logger;
+    }
+
+    @Override
+    public @NotNull Path getPluginSource() {
+        return this.pluginSource;
+    }
+}

paper-server/src/main/java/io/papermc/paper/plugin/bootstrap/PluginProviderContextImpl.java

@@ -0,0 +1,49 @@
+package io.papermc.paper.plugin.bootstrap;
+
+import io.papermc.paper.plugin.PluginInitializerManager;
+import io.papermc.paper.plugin.configuration.PluginMeta;
+import net.kyori.adventure.text.logger.slf4j.ComponentLogger;
+import org.jetbrains.annotations.NotNull;
+
+import java.nio.file.Path;
+
+public final class PluginProviderContextImpl implements PluginProviderContext {
+
+    private final PluginMeta config;
+    private final Path dataFolder;
+    private final ComponentLogger logger;
+    private final Path pluginSource;
+
+    public PluginProviderContextImpl(PluginMeta config, Path dataFolder, ComponentLogger logger, Path pluginSource) {
+        this.config = config;
+        this.dataFolder = dataFolder;
+        this.logger = logger;
+        this.pluginSource = pluginSource;
+    }
+
+    public static PluginProviderContextImpl create(PluginMeta config, ComponentLogger logger, Path pluginSource) {
+        Path dataFolder = PluginInitializerManager.instance().pluginDirectoryPath().resolve(config.getName());
+
+        return new PluginProviderContextImpl(config, dataFolder, logger, pluginSource);
+    }
+
+    @Override
+    public @NotNull PluginMeta getConfiguration() {
+        return this.config;
+    }
+
+    @Override
+    public @NotNull Path getDataDirectory() {
+        return this.dataFolder;
+    }
+
+    @Override
+    public @NotNull ComponentLogger getLogger() {
+        return this.logger;
+    }
+
+    @Override
+    public @NotNull Path getPluginSource() {
+        return this.pluginSource;
+    }
+}

paper-server/src/main/java/io/papermc/paper/plugin/entrypoint/Entrypoint.java

@@ -0,0 +1,25 @@
+package io.papermc.paper.plugin.entrypoint;
+
+import io.papermc.paper.plugin.bootstrap.PluginBootstrap;
+import org.bukkit.plugin.java.JavaPlugin;
+
+/**
+ * Used to mark a certain place that {@link EntrypointHandler} will register {@link io.papermc.paper.plugin.provider.PluginProvider} under.
+ * Used for loading only certain providers at a certain time.
+ * @param <T> provider type
+ */
+public final class Entrypoint<T> {
+
+    public static final Entrypoint<PluginBootstrap> BOOTSTRAPPER = new Entrypoint<>("bootstrapper");
+    public static final Entrypoint<JavaPlugin> PLUGIN = new Entrypoint<>("plugin");
+
+    private final String debugName;
+
+    private Entrypoint(String debugName) {
+        this.debugName = debugName;
+    }
+
+    public String getDebugName() {
+        return debugName;
+    }
+}

paper-server/src/main/java/io/papermc/paper/plugin/entrypoint/EntrypointHandler.java

@@ -0,0 +1,14 @@
+package io.papermc.paper.plugin.entrypoint;
+
+import io.papermc.paper.plugin.provider.PluginProvider;
+
+/**
+ * Represents a register that will register providers at a certain {@link Entrypoint},
+ * where then when the given {@link Entrypoint} is registered those will be loaded.
+ */
+public interface EntrypointHandler {
+
+    <T> void register(Entrypoint<T> entrypoint, PluginProvider<T> provider);
+
+    void enter(Entrypoint<?> entrypoint);
+}

paper-server/src/main/java/io/papermc/paper/plugin/entrypoint/LaunchEntryPointHandler.java

@@ -0,0 +1,74 @@
+package io.papermc.paper.plugin.entrypoint;
+
+import io.papermc.paper.plugin.provider.PluginProvider;
+import io.papermc.paper.plugin.storage.BootstrapProviderStorage;
+import io.papermc.paper.plugin.storage.ProviderStorage;
+import io.papermc.paper.plugin.storage.ServerPluginProviderStorage;
+import it.unimi.dsi.fastutil.objects.Object2BooleanMap;
+import it.unimi.dsi.fastutil.objects.Object2BooleanOpenHashMap;
+import org.jetbrains.annotations.ApiStatus;
+
+import java.util.HashMap;
+import java.util.Map;
+
+/**
+ * Used by the server to register/load plugin bootstrappers and plugins.
+ */
+public class LaunchEntryPointHandler implements EntrypointHandler {
+
+    public static final LaunchEntryPointHandler INSTANCE = new LaunchEntryPointHandler();
+    private final Map<Entrypoint<?>, ProviderStorage<?>> storage = new HashMap<>();
+    private final Object2BooleanMap<Entrypoint<?>> enteredMap = new Object2BooleanOpenHashMap<>();
+
+    LaunchEntryPointHandler() {
+        this.populateProviderStorage();
+        this.enteredMap.defaultReturnValue(false);
+    }
+
+    // Utility
+    public static void enterBootstrappers() {
+        LaunchEntryPointHandler.INSTANCE.enter(Entrypoint.BOOTSTRAPPER);
+    }
+
+    @Override
+    public void enter(Entrypoint<?> entrypoint) {
+        ProviderStorage<?> storage = this.storage.get(entrypoint);
+        if (storage == null) {
+            throw new IllegalArgumentException("No storage registered for entrypoint %s.".formatted(entrypoint));
+        }
+
+        storage.enter();
+        this.enteredMap.put(entrypoint, true);
+    }
+
+    @Override
+    public <T> void register(Entrypoint<T> entrypoint, PluginProvider<T> provider) {
+        ProviderStorage<T> storage = this.get(entrypoint);
+        if (storage == null) {
+            throw new IllegalArgumentException("No storage registered for entrypoint %s.".formatted(entrypoint));
+        }
+
+        storage.register(provider);
+    }
+
+    @SuppressWarnings("unchecked")
+    public <T> ProviderStorage<T> get(Entrypoint<T> entrypoint) {
+        return (ProviderStorage<T>) this.storage.get(entrypoint);
+    }
+
+    // Debug only
+    @ApiStatus.Internal
+    public Map<Entrypoint<?>, ProviderStorage<?>> getStorage() {
+        return storage;
+    }
+
+    public boolean hasEntered(Entrypoint<?> entrypoint) {
+        return this.enteredMap.getBoolean(entrypoint);
+    }
+
+    // Reload only
+    public void populateProviderStorage() {
+        this.storage.put(Entrypoint.BOOTSTRAPPER, new BootstrapProviderStorage());
+        this.storage.put(Entrypoint.PLUGIN, new ServerPluginProviderStorage());
+    }
+}

paper-server/src/main/java/io/papermc/paper/plugin/entrypoint/classloader/ClassloaderBytecodeModifier.java

@@ -0,0 +1,22 @@
+package io.papermc.paper.plugin.entrypoint.classloader;
+
+import io.papermc.paper.plugin.configuration.PluginMeta;
+import net.kyori.adventure.util.Services;
+import org.jetbrains.annotations.ApiStatus;
+
+@ApiStatus.Internal
+public interface ClassloaderBytecodeModifier {
+
+    static ClassloaderBytecodeModifier bytecodeModifier() {
+        return Provider.INSTANCE;
+    }
+
+    byte[] modify(PluginMeta config, byte[] bytecode);
+
+    class Provider {
+
+        private static final ClassloaderBytecodeModifier INSTANCE = Services.service(ClassloaderBytecodeModifier.class).orElseThrow();
+
+    }
+
+}

paper-server/src/main/java/io/papermc/paper/plugin/entrypoint/classloader/PaperClassloaderBytecodeModifier.java

@@ -0,0 +1,12 @@
+package io.papermc.paper.plugin.entrypoint.classloader;
+
+import io.papermc.paper.plugin.configuration.PluginMeta;
+
+// Stub, implement in future.
+public class PaperClassloaderBytecodeModifier implements ClassloaderBytecodeModifier {
+
+    @Override
+    public byte[] modify(PluginMeta configuration, byte[] bytecode) {
+        return bytecode;
+    }
+}

paper-server/src/main/java/io/papermc/paper/plugin/entrypoint/classloader/PaperPluginClassLoader.java

@@ -0,0 +1,209 @@
+package io.papermc.paper.plugin.entrypoint.classloader;
+
+import io.papermc.paper.plugin.configuration.PluginMeta;
+import io.papermc.paper.plugin.provider.entrypoint.DependencyContext;
+import io.papermc.paper.plugin.provider.classloader.ConfiguredPluginClassLoader;
+import io.papermc.paper.plugin.entrypoint.classloader.group.PaperPluginClassLoaderStorage;
+import io.papermc.paper.plugin.provider.classloader.PaperClassLoaderStorage;
+import io.papermc.paper.plugin.provider.classloader.PluginClassLoaderGroup;
+import io.papermc.paper.plugin.provider.configuration.PaperPluginMeta;
+import org.bukkit.Bukkit;
+import org.bukkit.plugin.PluginDescriptionFile;
+import org.bukkit.plugin.java.JavaPlugin;
+import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
+
+import java.io.File;
+import java.io.IOException;
+import java.net.URL;
+import java.net.URLClassLoader;
+import java.nio.file.Path;
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.Enumeration;
+import java.util.List;
+import java.util.Map;
+import java.util.Set;
+import java.util.concurrent.ConcurrentHashMap;
+import java.util.jar.JarFile;
+import java.util.logging.Logger;
+
+/**
+ * This is similar to a {@link org.bukkit.plugin.java.PluginClassLoader} but is completely kept hidden from the api.
+ * This is only used with Paper plugins.
+ *
+ * @see PaperPluginClassLoaderStorage
+ */
+public class PaperPluginClassLoader extends PaperSimplePluginClassLoader implements ConfiguredPluginClassLoader {
+
+    static {
+        registerAsParallelCapable();
+    }
+
+    private final URLClassLoader libraryLoader;
+    private final Set<String> seenIllegalAccess = Collections.newSetFromMap(new ConcurrentHashMap<>());
+    private final Logger logger;
+    @Nullable
+    private JavaPlugin loadedJavaPlugin;
+    @Nullable
+    private PluginClassLoaderGroup group;
+
+    public PaperPluginClassLoader(Logger logger, Path source, JarFile file, PaperPluginMeta configuration, ClassLoader parentLoader, URLClassLoader libraryLoader) throws IOException {
+        super(source, file, configuration, parentLoader);
+        this.libraryLoader = libraryLoader;
+
+        this.logger = logger;
+        if (this.configuration().hasOpenClassloader()) {
+            this.group = PaperClassLoaderStorage.instance().registerOpenGroup(this);
+        }
+    }
+
+    private PaperPluginMeta configuration() {
+        return (PaperPluginMeta) this.configuration;
+    }
+
+    public void refreshClassloaderDependencyTree(DependencyContext dependencyContext) {
+         if (this.configuration().hasOpenClassloader()) {
+             return;
+         }
+         if (this.group != null) {
+             // We need to unregister the classloader inorder to allow for dependencies
+             // to be recalculated
+             PaperClassLoaderStorage.instance().unregisterClassloader(this);
+         }
+
+        this.group = PaperClassLoaderStorage.instance().registerAccessBackedGroup(this, (classLoader) -> {
+            return dependencyContext.isTransitiveDependency(PaperPluginClassLoader.this.configuration, classLoader.getConfiguration());
+        });
+    }
+
+    @Override
+    public URL getResource(String name) {
+        URL resource = findResource(name);
+        if (resource == null && this.libraryLoader != null) {
+            return this.libraryLoader.getResource(name);
+        }
+        return resource;
+    }
+
+    @Override
+    public Enumeration<URL> getResources(String name) throws IOException {
+        List<URL> resources = new ArrayList<>();
+        this.addEnumeration(resources, this.findResources(name));
+        if (this.libraryLoader != null) {
+            addEnumeration(resources, this.libraryLoader.getResources(name));
+        }
+        return Collections.enumeration(resources);
+    }
+
+    private <T> void addEnumeration(List<T> list, Enumeration<T> enumeration) {
+        while (enumeration.hasMoreElements()) {
+            list.add(enumeration.nextElement());
+        }
+    }
+
+    @Override
+    protected Class<?> loadClass(String name, boolean resolve) throws ClassNotFoundException {
+        return this.loadClass(name, resolve, true, true);
+    }
+
+    @Override
+    public PluginMeta getConfiguration() {
+        return this.configuration;
+    }
+
+    @Override
+    public Class<?> loadClass(@NotNull String name, boolean resolve, boolean checkGroup, boolean checkLibraries) throws ClassNotFoundException {
+        try {
+            Class<?> result = super.loadClass(name, resolve);
+
+            // SPIGOT-6749: Library classes will appear in the above, but we don't want to return them to other plugins
+            if (checkGroup || result.getClassLoader() == this) {
+                return result;
+            }
+        } catch (ClassNotFoundException ignored) {
+        }
+
+        if (checkLibraries) {
+            try {
+                return this.libraryLoader.loadClass(name);
+            } catch (ClassNotFoundException ignored) {
+            }
+        }
+
+        if (checkGroup) {
+            // This ignores the libraries of other plugins, unless they are transitive dependencies.
+            if (this.group == null) {
+                throw new IllegalStateException("Tried to resolve class while group was not yet initialized");
+            }
+
+            Class<?> clazz = this.group.getClassByName(name, resolve, this);
+            if (clazz != null) {
+                return clazz;
+            }
+        }
+
+        throw new ClassNotFoundException(name);
+    }
+
+    @Override
+    public void init(JavaPlugin plugin) {
+        PluginMeta config = this.configuration;
+        PluginDescriptionFile pluginDescriptionFile = new PluginDescriptionFile(
+            config.getName(),
+            config.getName(),
+            config.getProvidedPlugins(),
+            config.getMainClass(),
+            "", // Classloader load order api
+            config.getPluginDependencies(), // Dependencies
+            config.getPluginSoftDependencies(), // Soft Depends
+            config.getLoadBeforePlugins(), // Load Before
+            config.getVersion(),
+            Map.of(), // Commands, we use a separate system
+            config.getDescription(),
+            config.getAuthors(),
+            config.getContributors(),
+            config.getWebsite(),
+            config.getLoggerPrefix(),
+            config.getLoadOrder(),
+            config.getPermissions(),
+            config.getPermissionDefault(),
+            Set.of(), // Aware api
+            config.getAPIVersion(),
+            List.of() // Libraries
+        );
+
+        File dataFolder = new File(Bukkit.getPluginsFolder(), pluginDescriptionFile.getName());
+
+        plugin.init(Bukkit.getServer(), pluginDescriptionFile, dataFolder, this.source.toFile(), this, config, this.logger);
+
+        this.loadedJavaPlugin = plugin;
+    }
+
+    @Nullable
+    @Override
+    public JavaPlugin getPlugin() {
+        return this.loadedJavaPlugin;
+    }
+
+    @Override
+    public String toString() {
+        return "PaperPluginClassLoader{" +
+            "libraryLoader=" + this.libraryLoader +
+            ", seenIllegalAccess=" + this.seenIllegalAccess +
+            ", loadedJavaPlugin=" + this.loadedJavaPlugin +
+            '}';
+    }
+
+    @Override
+    public void close() throws IOException {
+        try (this.jar; this.libraryLoader) {
+            super.close();
+        }
+    }
+
+    @Override
+    public @Nullable PluginClassLoaderGroup getGroup() {
+        return this.group;
+    }
+}

paper-server/src/main/java/io/papermc/paper/plugin/entrypoint/classloader/PaperSimplePluginClassLoader.java

@@ -0,0 +1,116 @@
+package io.papermc.paper.plugin.entrypoint.classloader;
+
+import io.papermc.paper.plugin.configuration.PluginMeta;
+import io.papermc.paper.plugin.util.NamespaceChecker;
+import org.jetbrains.annotations.ApiStatus;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.net.URL;
+import java.net.URLClassLoader;
+import java.nio.file.Path;
+import java.security.CodeSigner;
+import java.security.CodeSource;
+import java.util.Enumeration;
+import java.util.jar.JarEntry;
+import java.util.jar.JarFile;
+import java.util.jar.Manifest;
+
+/**
+ * Represents a simple classloader used for paper plugin bootstrappers.
+ */
+@ApiStatus.Internal
+public class PaperSimplePluginClassLoader extends URLClassLoader {
+
+    static {
+        ClassLoader.registerAsParallelCapable();
+    }
+
+    protected final PluginMeta configuration;
+    protected final Path source;
+    protected final Manifest jarManifest;
+    protected final URL jarUrl;
+    protected final JarFile jar;
+
+    public PaperSimplePluginClassLoader(Path source, JarFile file, PluginMeta configuration, ClassLoader parentLoader) throws IOException {
+        super(source.getFileName().toString(), new URL[]{source.toUri().toURL()}, parentLoader);
+
+        this.source = source;
+        this.jarManifest = file.getManifest();
+        this.jarUrl = source.toUri().toURL();
+        this.configuration = configuration;
+        this.jar = file;
+    }
+
+    @Override
+    public URL getResource(String name) {
+        return this.findResource(name);
+    }
+
+    @Override
+    public Enumeration<URL> getResources(String name) throws IOException {
+        return this.findResources(name);
+    }
+
+    // Bytecode modification supported loader
+    @Override
+    protected Class<?> findClass(String name) throws ClassNotFoundException {
+        NamespaceChecker.validateNameSpaceForClassloading(name);
+
+        // See UrlClassLoader#findClass(String)
+        String path = name.replace('.', '/').concat(".class");
+        JarEntry entry = this.jar.getJarEntry(path);
+        if (entry == null) {
+            throw new ClassNotFoundException(name);
+        }
+
+        // See URLClassLoader#defineClass(String, Resource)
+        byte[] classBytes;
+
+        try (InputStream is = this.jar.getInputStream(entry)) {
+            classBytes = is.readAllBytes();
+        } catch (IOException ex) {
+            throw new ClassNotFoundException(name, ex);
+        }
+
+        classBytes = ClassloaderBytecodeModifier.bytecodeModifier().modify(this.configuration, classBytes);
+
+        int dot = name.lastIndexOf('.');
+        if (dot != -1) {
+            String pkgName = name.substring(0, dot);
+            // Get defined package does not correctly handle sealed packages.
+            if (this.getDefinedPackage(pkgName) == null) {
+                try {
+                    if (this.jarManifest != null) {
+                        this.definePackage(pkgName, this.jarManifest, this.jarUrl);
+                    } else {
+                        this.definePackage(pkgName, null, null, null, null, null, null, null);
+                    }
+                } catch (IllegalArgumentException ex) {
+                    // parallel-capable class loaders: re-verify in case of a
+                    // race condition
+                    if (this.getDefinedPackage(pkgName) == null) {
+                        // Should never happen
+                        throw new IllegalStateException("Cannot find package " + pkgName);
+                    }
+                }
+            }
+        }
+
+        CodeSigner[] signers = entry.getCodeSigners();
+        CodeSource source = new CodeSource(this.jarUrl, signers);
+
+        return this.defineClass(name, classBytes, 0, classBytes.length, source);
+    }
+
+    @Override
+    public String toString() {
+        return "PaperSimplePluginClassLoader{" +
+            "configuration=" + this.configuration +
+            ", source=" + this.source +
+            ", jarManifest=" + this.jarManifest +
+            ", jarUrl=" + this.jarUrl +
+            ", jar=" + this.jar +
+            '}';
+    }
+}

paper-server/src/main/java/io/papermc/paper/plugin/entrypoint/classloader/group/DependencyBasedPluginClassLoaderGroup.java

@@ -0,0 +1,47 @@
+package io.papermc.paper.plugin.entrypoint.classloader.group;
+
+import io.papermc.paper.plugin.provider.classloader.ClassLoaderAccess;
+import io.papermc.paper.plugin.provider.classloader.ConfiguredPluginClassLoader;
+import org.jetbrains.annotations.ApiStatus;
+
+import java.util.ArrayList;
+
+@ApiStatus.Internal
+public class DependencyBasedPluginClassLoaderGroup extends SimpleListPluginClassLoaderGroup {
+
+    private final GlobalPluginClassLoaderGroup globalPluginClassLoaderGroup;
+    private final ClassLoaderAccess access;
+
+    public DependencyBasedPluginClassLoaderGroup(GlobalPluginClassLoaderGroup globalPluginClassLoaderGroup, ClassLoaderAccess access) {
+        super(new ArrayList<>());
+        this.access = access;
+        this.globalPluginClassLoaderGroup = globalPluginClassLoaderGroup;
+    }
+
+    /**
+     * This will refresh the dependencies of the current classloader.
+     */
+    public void populateDependencies() {
+        this.classloaders.clear();
+        for (ConfiguredPluginClassLoader configuredPluginClassLoader : this.globalPluginClassLoaderGroup.getClassLoaders()) {
+            if (this.access.canAccess(configuredPluginClassLoader)) {
+                this.classloaders.add(configuredPluginClassLoader);
+            }
+        }
+
+    }
+
+    @Override
+    public ClassLoaderAccess getAccess() {
+        return this.access;
+    }
+
+    @Override
+    public String toString() {
+        return "DependencyBasedPluginClassLoaderGroup{" +
+            "globalPluginClassLoaderGroup=" + this.globalPluginClassLoaderGroup +
+            ", access=" + this.access +
+            ", classloaders=" + this.classloaders +
+            '}';
+    }
+}

paper-server/src/main/java/io/papermc/paper/plugin/entrypoint/classloader/group/GlobalPluginClassLoaderGroup.java

@@ -0,0 +1,18 @@
+package io.papermc.paper.plugin.entrypoint.classloader.group;
+
+import io.papermc.paper.plugin.provider.classloader.ClassLoaderAccess;
+import org.jetbrains.annotations.ApiStatus;
+
+@ApiStatus.Internal
+public class GlobalPluginClassLoaderGroup extends SimpleListPluginClassLoaderGroup {
+
+    @Override
+    public ClassLoaderAccess getAccess() {
+        return (v) -> true;
+    }
+
+    @Override
+    public String toString() {
+        return "GLOBAL:" + super.toString();
+    }
+}

paper-server/src/main/java/io/papermc/paper/plugin/entrypoint/classloader/group/LockingClassLoaderGroup.java

@@ -0,0 +1,76 @@
+package io.papermc.paper.plugin.entrypoint.classloader.group;
+
+import io.papermc.paper.plugin.provider.classloader.ClassLoaderAccess;
+import io.papermc.paper.plugin.provider.classloader.ConfiguredPluginClassLoader;
+import io.papermc.paper.plugin.provider.classloader.PluginClassLoaderGroup;
+import org.jetbrains.annotations.ApiStatus;
+import org.jetbrains.annotations.Nullable;
+
+import java.util.HashMap;
+import java.util.Map;
+import java.util.concurrent.atomic.AtomicInteger;
+import java.util.concurrent.locks.ReentrantReadWriteLock;
+
+@ApiStatus.Internal
+public class LockingClassLoaderGroup implements PluginClassLoaderGroup {
+
+    private final PluginClassLoaderGroup parent;
+    private final Map<String, ClassLockEntry> classLoadLock = new HashMap<>();
+
+    public LockingClassLoaderGroup(PluginClassLoaderGroup parent) {
+        this.parent = parent;
+    }
+
+    @Override
+    public @Nullable Class<?> getClassByName(String name, boolean resolve, ConfiguredPluginClassLoader requester) {
+        // make MT safe
+        ClassLockEntry lock;
+        synchronized (this.classLoadLock) {
+            lock = this.classLoadLock.computeIfAbsent(name, (x) -> new ClassLockEntry(new AtomicInteger(0), new java.util.concurrent.locks.ReentrantReadWriteLock()));
+            lock.count.incrementAndGet();
+        }
+        lock.reentrantReadWriteLock.writeLock().lock();
+        try {
+            return parent.getClassByName(name, resolve, requester);
+        } finally {
+            synchronized (this.classLoadLock) {
+                lock.reentrantReadWriteLock.writeLock().unlock();
+                if (lock.count.get() == 1) {
+                    this.classLoadLock.remove(name);
+                } else {
+                    lock.count.decrementAndGet();
+                }
+            }
+        }
+    }
+
+    @Override
+    public void remove(ConfiguredPluginClassLoader configuredPluginClassLoader) {
+        this.parent.remove(configuredPluginClassLoader);
+    }
+
+    @Override
+    public void add(ConfiguredPluginClassLoader configuredPluginClassLoader) {
+        this.parent.add(configuredPluginClassLoader);
+    }
+
+    @Override
+    public ClassLoaderAccess getAccess() {
+        return this.parent.getAccess();
+    }
+
+    public PluginClassLoaderGroup getParent() {
+        return parent;
+    }
+
+    record ClassLockEntry(AtomicInteger count, ReentrantReadWriteLock reentrantReadWriteLock) {
+    }
+
+    @Override
+    public String toString() {
+        return "LockingClassLoaderGroup{" +
+            "parent=" + this.parent +
+            ", classLoadLock=" + this.classLoadLock +
+            '}';
+    }
+}

paper-server/src/main/java/io/papermc/paper/plugin/entrypoint/classloader/group/PaperPluginClassLoaderStorage.java

@@ -0,0 +1,93 @@
+package io.papermc.paper.plugin.entrypoint.classloader.group;
+
+import io.papermc.paper.plugin.provider.classloader.ClassLoaderAccess;
+import io.papermc.paper.plugin.provider.classloader.ConfiguredPluginClassLoader;
+import io.papermc.paper.plugin.provider.classloader.PaperClassLoaderStorage;
+import io.papermc.paper.plugin.provider.classloader.PluginClassLoaderGroup;
+import org.bukkit.plugin.java.PluginClassLoader;
+import org.jetbrains.annotations.ApiStatus;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.concurrent.CopyOnWriteArrayList;
+
+/**
+ * This is used for connecting multiple classloaders.
+ */
+public final class PaperPluginClassLoaderStorage implements PaperClassLoaderStorage {
+
+    private final GlobalPluginClassLoaderGroup globalGroup = new GlobalPluginClassLoaderGroup();
+    private final List<PluginClassLoaderGroup> groups = new CopyOnWriteArrayList<>();
+
+    public PaperPluginClassLoaderStorage() {
+        this.groups.add(this.globalGroup);
+    }
+
+    @Override
+    public PluginClassLoaderGroup registerSpigotGroup(PluginClassLoader pluginClassLoader) {
+        return this.registerGroup(pluginClassLoader, new SpigotPluginClassLoaderGroup(this.globalGroup, (library) -> {
+            return pluginClassLoader.dependencyContext.isTransitiveDependency(pluginClassLoader.getConfiguration(), library.getConfiguration());
+        }, pluginClassLoader));
+    }
+
+    @Override
+    public PluginClassLoaderGroup registerOpenGroup(ConfiguredPluginClassLoader classLoader) {
+        return this.registerGroup(classLoader, this.globalGroup);
+    }
+
+    @Override
+    public PluginClassLoaderGroup registerAccessBackedGroup(ConfiguredPluginClassLoader classLoader, ClassLoaderAccess access) {
+        List<ConfiguredPluginClassLoader> allowedLoaders = new ArrayList<>();
+        for (ConfiguredPluginClassLoader configuredPluginClassLoader : this.globalGroup.getClassLoaders()) {
+            if (access.canAccess(configuredPluginClassLoader)) {
+                allowedLoaders.add(configuredPluginClassLoader);
+            }
+        }
+
+        return this.registerGroup(classLoader, new StaticPluginClassLoaderGroup(allowedLoaders, access, classLoader));
+    }
+
+    private PluginClassLoaderGroup registerGroup(ConfiguredPluginClassLoader classLoader, PluginClassLoaderGroup group) {
+        // Now add this classloader to any groups that allows it (includes global)
+        for (PluginClassLoaderGroup loaderGroup : this.groups) {
+            if (loaderGroup.getAccess().canAccess(classLoader)) {
+                loaderGroup.add(classLoader);
+            }
+        }
+
+        group = new LockingClassLoaderGroup(group);
+        this.groups.add(group);
+        return group;
+    }
+
+    @Override
+    public void unregisterClassloader(ConfiguredPluginClassLoader configuredPluginClassLoader) {
+        this.globalGroup.remove(configuredPluginClassLoader);
+        this.groups.remove(configuredPluginClassLoader.getGroup());
+        for (PluginClassLoaderGroup group : this.groups) {
+            group.remove(configuredPluginClassLoader);
+        }
+    }
+
+    @Override
+    public boolean registerUnsafePlugin(ConfiguredPluginClassLoader pluginLoader) {
+        if (this.globalGroup.getClassLoaders().contains(pluginLoader)) {
+            return false;
+        } else {
+            this.globalGroup.add(pluginLoader);
+            return true;
+        }
+    }
+
+    // Debug only
+    @ApiStatus.Internal
+    public GlobalPluginClassLoaderGroup getGlobalGroup() {
+        return this.globalGroup;
+    }
+
+    // Debug only
+    @ApiStatus.Internal
+    public List<PluginClassLoaderGroup> getGroups() {
+        return this.groups;
+    }
+}

paper-server/src/main/java/io/papermc/paper/plugin/entrypoint/classloader/group/SimpleListPluginClassLoaderGroup.java

@@ -0,0 +1,69 @@
+package io.papermc.paper.plugin.entrypoint.classloader.group;
+
+import io.papermc.paper.plugin.provider.classloader.ConfiguredPluginClassLoader;
+import io.papermc.paper.plugin.provider.classloader.PluginClassLoaderGroup;
+import org.jetbrains.annotations.ApiStatus;
+import org.jetbrains.annotations.Nullable;
+
+import java.util.List;
+import java.util.concurrent.CopyOnWriteArrayList;
+
+@ApiStatus.Internal
+public abstract class SimpleListPluginClassLoaderGroup implements PluginClassLoaderGroup {
+
+    private static final boolean DISABLE_CLASS_PRIORITIZATION = Boolean.getBoolean("Paper.DisableClassPrioritization");
+
+    protected final List<ConfiguredPluginClassLoader> classloaders;
+
+    protected SimpleListPluginClassLoaderGroup() {
+        this(new CopyOnWriteArrayList<>());
+    }
+
+    protected SimpleListPluginClassLoaderGroup(List<ConfiguredPluginClassLoader> classloaders) {
+        this.classloaders = classloaders;
+    }
+
+    @Override
+    public @Nullable Class<?> getClassByName(String name, boolean resolve, ConfiguredPluginClassLoader requester) {
+        if (!DISABLE_CLASS_PRIORITIZATION) {
+            try {
+                return this.lookupClass(name, false, requester); // First check the requester
+            } catch (ClassNotFoundException ignored) {
+            }
+        }
+
+        for (ConfiguredPluginClassLoader loader : this.classloaders) {
+            try {
+                return this.lookupClass(name, resolve, loader);
+            } catch (ClassNotFoundException ignored) {
+            }
+        }
+
+        return null;
+    }
+
+    protected Class<?> lookupClass(String name, boolean resolve, ConfiguredPluginClassLoader current) throws ClassNotFoundException {
+        return current.loadClass(name, resolve, false, true);
+    }
+
+    @Override
+    public void remove(ConfiguredPluginClassLoader configuredPluginClassLoader) {
+        this.classloaders.remove(configuredPluginClassLoader);
+    }
+
+    @Override
+    public void add(ConfiguredPluginClassLoader configuredPluginClassLoader) {
+        this.classloaders.add(configuredPluginClassLoader);
+    }
+
+    public List<ConfiguredPluginClassLoader> getClassLoaders() {
+        return classloaders;
+    }
+
+    @Override
+    public String toString() {
+        return "SimpleListPluginClassLoaderGroup{" +
+            "classloaders=" + this.classloaders +
+            '}';
+    }
+}

paper-server/src/main/java/io/papermc/paper/plugin/entrypoint/classloader/group/SingletonPluginClassLoaderGroup.java

@@ -0,0 +1,60 @@
+package io.papermc.paper.plugin.entrypoint.classloader.group;
+
+import io.papermc.paper.plugin.provider.classloader.ClassLoaderAccess;
+import io.papermc.paper.plugin.provider.classloader.ConfiguredPluginClassLoader;
+import io.papermc.paper.plugin.provider.classloader.PluginClassLoaderGroup;
+import org.jetbrains.annotations.ApiStatus;
+import org.jetbrains.annotations.Nullable;
+
+@ApiStatus.Internal
+public class SingletonPluginClassLoaderGroup implements PluginClassLoaderGroup {
+
+    private final ConfiguredPluginClassLoader configuredPluginClassLoader;
+    private final Access access;
+
+    public SingletonPluginClassLoaderGroup(ConfiguredPluginClassLoader configuredPluginClassLoader) {
+        this.configuredPluginClassLoader = configuredPluginClassLoader;
+        this.access = new Access();
+    }
+
+    @Override
+    public @Nullable Class<?> getClassByName(String name, boolean resolve, ConfiguredPluginClassLoader requester) {
+        try {
+            return this.configuredPluginClassLoader.loadClass(name, resolve, false, true);
+        } catch (ClassNotFoundException ignored) {
+        }
+
+        return null;
+    }
+
+    @Override
+    public void remove(ConfiguredPluginClassLoader configuredPluginClassLoader) {
+    }
+
+    @Override
+    public void add(ConfiguredPluginClassLoader configuredPluginClassLoader) {
+    }
+
+    @Override
+    public ClassLoaderAccess getAccess() {
+        return this.access;
+    }
+
+    @ApiStatus.Internal
+    private class Access implements ClassLoaderAccess {
+
+        @Override
+        public boolean canAccess(ConfiguredPluginClassLoader classLoader) {
+            return SingletonPluginClassLoaderGroup.this.configuredPluginClassLoader == classLoader;
+        }
+
+    }
+
+    @Override
+    public String toString() {
+        return "SingletonPluginClassLoaderGroup{" +
+            "configuredPluginClassLoader=" + this.configuredPluginClassLoader +
+            ", access=" + this.access +
+            '}';
+    }
+}

paper-server/src/main/java/io/papermc/paper/plugin/entrypoint/classloader/group/SpigotPluginClassLoaderGroup.java

@@ -0,0 +1,58 @@
+package io.papermc.paper.plugin.entrypoint.classloader.group;
+
+import io.papermc.paper.plugin.provider.classloader.ClassLoaderAccess;
+import io.papermc.paper.plugin.provider.classloader.ConfiguredPluginClassLoader;
+import org.bukkit.plugin.java.PluginClassLoader;
+import org.jetbrains.annotations.ApiStatus;
+
+import java.util.function.Predicate;
+
+/**
+ * Spigot classloaders have the ability to see everything.
+ * However, libraries are ONLY shared depending on their dependencies.
+ */
+@ApiStatus.Internal
+public class SpigotPluginClassLoaderGroup extends SimpleListPluginClassLoaderGroup {
+
+    private final Predicate<ConfiguredPluginClassLoader> libraryClassloaderPredicate;
+    private final PluginClassLoader pluginClassLoader;
+
+    public SpigotPluginClassLoaderGroup(GlobalPluginClassLoaderGroup globalPluginClassLoaderGroup, Predicate<ConfiguredPluginClassLoader> libraryClassloaderPredicate, PluginClassLoader pluginClassLoader) {
+        super(globalPluginClassLoaderGroup.getClassLoaders());
+        this.libraryClassloaderPredicate = libraryClassloaderPredicate;
+        this.pluginClassLoader = pluginClassLoader;
+    }
+
+    // Mirrors global list
+    @Override
+    public void add(ConfiguredPluginClassLoader configuredPluginClassLoader) {
+    }
+
+    @Override
+    public void remove(ConfiguredPluginClassLoader configuredPluginClassLoader) {
+    }
+
+    // Don't allow other plugins to access spigot dependencies, they should instead reference the global list
+    @Override
+    public ClassLoaderAccess getAccess() {
+        return v -> false;
+    }
+
+    @Override
+    protected Class<?> lookupClass(String name, boolean resolve, ConfiguredPluginClassLoader current) throws ClassNotFoundException {
+        return current.loadClass(name, resolve, false, this.libraryClassloaderPredicate.test(current));
+    }
+
+    // DEBUG
+    public PluginClassLoader getPluginClassLoader() {
+        return pluginClassLoader;
+    }
+
+    @Override
+    public String toString() {
+        return "SpigotPluginClassLoaderGroup{" +
+            "libraryClassloaderPredicate=" + this.libraryClassloaderPredicate +
+            ", classloaders=" + this.classloaders +
+            '}';
+    }
+}

paper-server/src/main/java/io/papermc/paper/plugin/entrypoint/classloader/group/StaticPluginClassLoaderGroup.java

@@ -0,0 +1,40 @@
+package io.papermc.paper.plugin.entrypoint.classloader.group;
+
+import io.papermc.paper.plugin.provider.classloader.ClassLoaderAccess;
+import io.papermc.paper.plugin.provider.classloader.ConfiguredPluginClassLoader;
+import org.jetbrains.annotations.ApiStatus;
+
+import java.util.List;
+
+@ApiStatus.Internal
+public class StaticPluginClassLoaderGroup extends SimpleListPluginClassLoaderGroup {
+
+    private final ClassLoaderAccess access;
+    // Debug only
+    private final ConfiguredPluginClassLoader mainClassloaderHolder;
+
+    public StaticPluginClassLoaderGroup(List<ConfiguredPluginClassLoader> classloaders, ClassLoaderAccess access, ConfiguredPluginClassLoader mainClassloaderHolder) {
+        super(classloaders);
+        this.access = access;
+        this.mainClassloaderHolder = mainClassloaderHolder;
+    }
+
+    @Override
+    public ClassLoaderAccess getAccess() {
+        return this.access;
+    }
+
+    // DEBUG
+    @ApiStatus.Internal
+    public ConfiguredPluginClassLoader getPluginClassloader() {
+        return this.mainClassloaderHolder;
+    }
+
+    @Override
+    public String toString() {
+        return "StaticPluginClassLoaderGroup{" +
+            "access=" + this.access +
+            ", classloaders=" + this.classloaders +
+            '}';
+    }
+}

paper-server/src/main/java/io/papermc/paper/plugin/entrypoint/dependency/BootstrapMetaDependencyTree.java

@@ -0,0 +1,44 @@
+package io.papermc.paper.plugin.entrypoint.dependency;
+
+import com.google.common.graph.GraphBuilder;
+import com.google.common.graph.MutableGraph;
+import io.papermc.paper.plugin.configuration.PluginMeta;
+import io.papermc.paper.plugin.provider.configuration.PaperPluginMeta;
+
+public class BootstrapMetaDependencyTree extends MetaDependencyTree {
+    public BootstrapMetaDependencyTree() {
+        this(GraphBuilder.directed().build());
+    }
+
+    public BootstrapMetaDependencyTree(MutableGraph<String> graph) {
+        super(graph);
+    }
+
+    @Override
+    protected void registerDependencies(final String identifier, final PluginMeta meta) {
+        if (!(meta instanceof PaperPluginMeta paperPluginMeta)) {
+            throw new IllegalStateException("Only paper plugins can have a bootstrapper!");
+        }
+        // Build a validated provider's dependencies into the graph
+        for (String dependency : paperPluginMeta.getBootstrapDependencies().keySet()) {
+            this.graph.putEdge(identifier, dependency);
+        }
+    }
+
+    @Override
+    protected void unregisterDependencies(final String identifier, final PluginMeta meta) {
+        if (!(meta instanceof PaperPluginMeta paperPluginMeta)) {
+            throw new IllegalStateException("PluginMeta must be a PaperPluginMeta");
+        }
+
+        // Build a validated provider's dependencies into the graph
+        for (String dependency : paperPluginMeta.getBootstrapDependencies().keySet()) {
+            this.graph.removeEdge(identifier, dependency);
+        }
+    }
+
+    @Override
+    public String toString() {
+        return "BootstrapDependencyTree{" + "graph=" + this.graph + '}';
+    }
+}

paper-server/src/main/java/io/papermc/paper/plugin/entrypoint/dependency/DependencyContextHolder.java

@@ -0,0 +1,9 @@
+package io.papermc.paper.plugin.entrypoint.dependency;
+
+import io.papermc.paper.plugin.provider.entrypoint.DependencyContext;
+
+public interface DependencyContextHolder {
+
+    void setContext(DependencyContext context);
+
+}

paper-server/src/main/java/io/papermc/paper/plugin/entrypoint/dependency/GraphDependencyContext.java

@@ -0,0 +1,54 @@
+package io.papermc.paper.plugin.entrypoint.dependency;
+
+import com.google.common.graph.Graph;
+import com.google.common.graph.Graphs;
+import com.google.common.graph.MutableGraph;
+import io.papermc.paper.plugin.configuration.PluginMeta;
+import io.papermc.paper.plugin.provider.entrypoint.DependencyContext;
+
+import java.util.Set;
+
+@SuppressWarnings("UnstableApiUsage")
+public class GraphDependencyContext implements DependencyContext {
+
+    private final MutableGraph<String> dependencyGraph;
+
+    public GraphDependencyContext(MutableGraph<String> dependencyGraph) {
+        this.dependencyGraph = dependencyGraph;
+    }
+
+    @Override
+    public boolean isTransitiveDependency(PluginMeta plugin, PluginMeta depend) {
+        String pluginIdentifier = plugin.getName();
+
+        if (this.dependencyGraph.nodes().contains(pluginIdentifier)) {
+            Set<String> reachableNodes = Graphs.reachableNodes(this.dependencyGraph, pluginIdentifier);
+            if (reachableNodes.contains(depend.getName())) {
+                return true;
+            }
+            for (String provided : depend.getProvidedPlugins()) {
+                if (reachableNodes.contains(provided)) {
+                    return true;
+                }
+            }
+        }
+
+        return false;
+    }
+
+    @Override
+    public boolean hasDependency(String pluginIdentifier) {
+        return this.dependencyGraph.nodes().contains(pluginIdentifier);
+    }
+
+    public MutableGraph<String> getDependencyGraph() {
+        return dependencyGraph;
+    }
+
+    @Override
+    public String toString() {
+        return "GraphDependencyContext{" +
+            "dependencyGraph=" + this.dependencyGraph +
+            '}';
+    }
+}

paper-server/src/main/java/io/papermc/paper/plugin/entrypoint/dependency/MetaDependencyTree.java

@@ -0,0 +1,110 @@
+package io.papermc.paper.plugin.entrypoint.dependency;
+
+import com.google.common.graph.GraphBuilder;
+import com.google.common.graph.Graphs;
+import com.google.common.graph.MutableGraph;
+import io.papermc.paper.plugin.configuration.PluginMeta;
+import io.papermc.paper.plugin.provider.PluginProvider;
+import io.papermc.paper.plugin.provider.entrypoint.DependencyContext;
+import org.jetbrains.annotations.NotNull;
+import java.util.HashSet;
+import java.util.Set;
+
+public abstract class MetaDependencyTree implements DependencyContext {
+
+    protected final MutableGraph<String> graph;
+
+    // We need to upkeep a separate collection since when populating
+    // a graph it adds nodes even if they are not present
+    protected final Set<String> dependencies = new HashSet<>();
+
+    public MetaDependencyTree() {
+        this(GraphBuilder.directed().build());
+    }
+
+    public MetaDependencyTree(MutableGraph<String> graph) {
+        this.graph = graph;
+    }
+
+    public void add(PluginMeta configuration) {
+        String identifier = configuration.getName();
+        // Build a validated provider's dependencies into the graph
+        this.registerDependencies(identifier, configuration);
+
+        this.graph.addNode(identifier); // Make sure dependencies at least have a node
+
+        // Add the provided plugins to the graph as well
+        for (String provides : configuration.getProvidedPlugins()) {
+            this.graph.putEdge(identifier, provides);
+            this.dependencies.add(provides);
+        }
+        this.dependencies.add(identifier);
+    }
+
+    protected abstract void registerDependencies(String identifier, PluginMeta meta);
+
+    public void remove(PluginMeta configuration) {
+        String identifier = configuration.getName();
+        // Remove a validated provider's dependencies into the graph
+        this.unregisterDependencies(identifier, configuration);
+
+        this.graph.removeNode(identifier); // Remove root node
+
+        // Remove the provided plugins to the graph as well
+        for (String provides : configuration.getProvidedPlugins()) {
+            this.graph.removeEdge(identifier, provides);
+            this.dependencies.remove(provides);
+        }
+        this.dependencies.remove(identifier);
+    }
+
+    protected abstract void unregisterDependencies(String identifier, PluginMeta meta);
+
+    @Override
+    public boolean isTransitiveDependency(@NotNull PluginMeta plugin, @NotNull PluginMeta depend) {
+        String pluginIdentifier = plugin.getName();
+
+        if (this.graph.nodes().contains(pluginIdentifier)) {
+            Set<String> reachableNodes = Graphs.reachableNodes(this.graph, pluginIdentifier);
+            if (reachableNodes.contains(depend.getName())) {
+                return true;
+            }
+            for (String provided : depend.getProvidedPlugins()) {
+                if (reachableNodes.contains(provided)) {
+                    return true;
+                }
+            }
+        }
+
+        return false;
+    }
+
+    @Override
+    public boolean hasDependency(@NotNull String pluginIdentifier) {
+        return this.dependencies.contains(pluginIdentifier);
+    }
+
+    public void addDirectDependency(String dependency) {
+        this.dependencies.add(dependency);
+    }
+
+    @Override
+    public String toString() {
+        return "SimpleDependencyTree{" +
+            "graph=" + this.graph +
+            '}';
+    }
+
+    public MutableGraph<String> getGraph() {
+        return graph;
+    }
+
+    public void add(PluginProvider<?> provider) {
+        this.add(provider.getMeta());
+    }
+
+    public void remove(PluginProvider<?> provider) {
+        this.remove(provider.getMeta());
+    }
+
+}

paper-server/src/main/java/io/papermc/paper/plugin/entrypoint/dependency/SimpleMetaDependencyTree.java

@@ -0,0 +1,40 @@
+package io.papermc.paper.plugin.entrypoint.dependency;
+
+import com.google.common.graph.GraphBuilder;
+import com.google.common.graph.Graphs;
+import com.google.common.graph.MutableGraph;
+import io.papermc.paper.plugin.configuration.PluginMeta;
+import org.jetbrains.annotations.NotNull;
+
+import java.util.HashSet;
+import java.util.Set;
+
+public class SimpleMetaDependencyTree extends MetaDependencyTree {
+
+    public SimpleMetaDependencyTree() {
+    }
+
+    public SimpleMetaDependencyTree(final MutableGraph<String> graph) {
+        super(graph);
+    }
+
+    @Override
+    protected void registerDependencies(final String identifier, final PluginMeta meta) {
+        for (String dependency : meta.getPluginDependencies()) {
+            this.graph.putEdge(identifier, dependency);
+        }
+        for (String dependency : meta.getPluginSoftDependencies()) {
+            this.graph.putEdge(identifier, dependency);
+        }
+    }
+
+    @Override
+    protected void unregisterDependencies(final String identifier, final PluginMeta meta) {
+        for (String dependency : meta.getPluginDependencies()) {
+            this.graph.removeEdge(identifier, dependency);
+        }
+        for (String dependency : meta.getPluginSoftDependencies()) {
+            this.graph.removeEdge(identifier, dependency);
+        }
+    }
+}

paper-server/src/main/java/io/papermc/paper/plugin/entrypoint/strategy/JohnsonSimpleCycles.java

@@ -0,0 +1,354 @@
+/*
+ * (C) Copyright 2013-2021, by Nikolay Ognyanov and Contributors.
+ *
+ * JGraphT : a free Java graph-theory library
+ *
+ * See the CONTRIBUTORS.md file distributed with this work for additional
+ * information regarding copyright ownership.
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Eclipse Public License 2.0 which is available at
+ * http://www.eclipse.org/legal/epl-2.0, or the
+ * GNU Lesser General Public License v2.1 or later
+ * which is available at
+ * http://www.gnu.org/licenses/old-licenses/lgpl-2.1-standalone.html.
+ *
+ * SPDX-License-Identifier: EPL-2.0 OR LGPL-2.1-or-later
+ */
+
+// MODIFICATIONS:
+// - Modified to use a guava graph directly
+
+package io.papermc.paper.plugin.entrypoint.strategy;
+
+import com.google.common.base.Preconditions;
+import com.google.common.graph.Graph;
+import com.google.common.graph.GraphBuilder;
+import com.google.common.graph.MutableGraph;
+import com.mojang.datafixers.util.Pair;
+
+import java.util.ArrayDeque;
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.HashSet;
+import java.util.List;
+import java.util.Map;
+import java.util.Set;
+import java.util.function.BiConsumer;
+import java.util.function.Consumer;
+
+/**
+ * Find all simple cycles of a directed graph using the Johnson's algorithm.
+ *
+ * <p>
+ * See:<br>
+ * D.B.Johnson, Finding all the elementary circuits of a directed graph, SIAM J. Comput., 4 (1975),
+ * pp. 77-84.
+ *
+ * @param <V> the vertex type.
+ *
+ * @author Nikolay Ognyanov
+ */
+public class JohnsonSimpleCycles<V>
+{
+    // The graph.
+    private Graph<V> graph;
+
+    // The main state of the algorithm.
+    private Consumer<List<V>> cycleConsumer = null;
+    private BiConsumer<V, V> cycleVertexSuccessorConsumer = null; // Paper
+    private V[] iToV = null;
+    private Map<V, Integer> vToI = null;
+    private Set<V> blocked = null;
+    private Map<V, Set<V>> bSets = null;
+    private ArrayDeque<V> stack = null;
+
+    // The state of the embedded Tarjan SCC algorithm.
+    private List<Set<V>> foundSCCs = null;
+    private int index = 0;
+    private Map<V, Integer> vIndex = null;
+    private Map<V, Integer> vLowlink = null;
+    private ArrayDeque<V> path = null;
+    private Set<V> pathSet = null;
+
+    /**
+     * Create a simple cycle finder for the specified graph.
+     *
+     * @param graph - the DirectedGraph in which to find cycles.
+     *
+     * @throws IllegalArgumentException if the graph argument is <code>
+     * null</code>.
+     */
+    public JohnsonSimpleCycles(Graph<V> graph)
+    {
+        Preconditions.checkState(graph.isDirected(), "Graph must be directed");
+        this.graph = graph;
+    }
+
+    /**
+     * Find the simple cycles of the graph.
+     *
+     * @return The list of all simple cycles. Possibly empty but never <code>null</code>.
+     */
+    public List<List<V>> findAndRemoveSimpleCycles()
+    {
+        List<List<V>> result = new ArrayList<>();
+        findSimpleCycles(result::add, (v, s) -> ((MutableGraph<V>) graph).removeEdge(v, s)); // Paper
+        return result;
+    }
+
+    /**
+     * Find the simple cycles of the graph.
+     *
+     * @param consumer Consumer that will be called with each cycle found.
+     */
+    public void findSimpleCycles(Consumer<List<V>> consumer, BiConsumer<V, V> vertexSuccessorConsumer) // Paper
+    {
+        if (graph == null) {
+            throw new IllegalArgumentException("Null graph.");
+        }
+        cycleVertexSuccessorConsumer = vertexSuccessorConsumer; // Paper
+        initState(consumer);
+
+        int startIndex = 0;
+        int size = graph.nodes().size();
+        while (startIndex < size) {
+            Pair<Graph<V>, Integer> minSCCGResult = findMinSCSG(startIndex);
+            if (minSCCGResult != null) {
+                startIndex = minSCCGResult.getSecond();
+                Graph<V> scg = minSCCGResult.getFirst();
+                V startV = toV(startIndex);
+                for (V v : scg.successors(startV)) {
+                    blocked.remove(v);
+                    getBSet(v).clear();
+                }
+                findCyclesInSCG(startIndex, startIndex, scg);
+                startIndex++;
+            } else {
+                break;
+            }
+        }
+
+        clearState();
+    }
+
+    private Pair<Graph<V>, Integer> findMinSCSG(int startIndex)
+    {
+        /*
+         * Per Johnson : "adjacency structure of strong component $K$ with least vertex in subgraph
+         * of $G$ induced by $(s, s + 1, n)$". Or in contemporary terms: the strongly connected
+         * component of the subgraph induced by $(v_1, \dotso ,v_n)$ which contains the minimum
+         * (among those SCCs) vertex index. We return that index together with the graph.
+         */
+        initMinSCGState();
+
+        List<Set<V>> foundSCCs = findSCCS(startIndex);
+
+        // find the SCC with the minimum index
+        int minIndexFound = Integer.MAX_VALUE;
+        Set<V> minSCC = null;
+        for (Set<V> scc : foundSCCs) {
+            for (V v : scc) {
+                int t = toI(v);
+                if (t < minIndexFound) {
+                    minIndexFound = t;
+                    minSCC = scc;
+                }
+            }
+        }
+        if (minSCC == null) {
+            return null;
+        }
+
+        // build a graph for the SCC found
+        MutableGraph<V> dependencyGraph = GraphBuilder.directed().allowsSelfLoops(true).build();
+
+        for (V v : minSCC) {
+            for (V w : minSCC) {
+                if (graph.hasEdgeConnecting(v, w)) {
+                    dependencyGraph.putEdge(v, w);
+                }
+            }
+        }
+
+        Pair<Graph<V>, Integer> result = Pair.of(dependencyGraph, minIndexFound);
+        clearMinSCCState();
+        return result;
+    }
+
+    private List<Set<V>> findSCCS(int startIndex)
+    {
+        // Find SCCs in the subgraph induced
+        // by vertices startIndex and beyond.
+        // A call to StrongConnectivityAlgorithm
+        // would be too expensive because of the
+        // need to materialize the subgraph.
+        // So - do a local search by the Tarjan's
+        // algorithm and pretend that vertices
+        // with an index smaller than startIndex
+        // do not exist.
+        for (V v : graph.nodes()) {
+            int vI = toI(v);
+            if (vI < startIndex) {
+                continue;
+            }
+            if (!vIndex.containsKey(v)) {
+                getSCCs(startIndex, vI);
+            }
+        }
+        List<Set<V>> result = foundSCCs;
+        foundSCCs = null;
+        return result;
+    }
+
+    private void getSCCs(int startIndex, int vertexIndex)
+    {
+        V vertex = toV(vertexIndex);
+        vIndex.put(vertex, index);
+        vLowlink.put(vertex, index);
+        index++;
+        path.push(vertex);
+        pathSet.add(vertex);
+
+        Set<V> edges = graph.successors(vertex);
+        for (V successor : edges) {
+            int successorIndex = toI(successor);
+            if (successorIndex < startIndex) {
+                continue;
+            }
+            if (!vIndex.containsKey(successor)) {
+                getSCCs(startIndex, successorIndex);
+                vLowlink.put(vertex, Math.min(vLowlink.get(vertex), vLowlink.get(successor)));
+            } else if (pathSet.contains(successor)) {
+                vLowlink.put(vertex, Math.min(vLowlink.get(vertex), vIndex.get(successor)));
+            }
+        }
+        if (vLowlink.get(vertex).equals(vIndex.get(vertex))) {
+            Set<V> result = new HashSet<>();
+            V temp;
+            do {
+                temp = path.pop();
+                pathSet.remove(temp);
+                result.add(temp);
+            } while (!vertex.equals(temp));
+            if (result.size() == 1) {
+                V v = result.iterator().next();
+                if (graph.edges().contains(vertex)) {
+                    foundSCCs.add(result);
+                }
+            } else {
+                foundSCCs.add(result);
+            }
+        }
+    }
+
+    private boolean findCyclesInSCG(int startIndex, int vertexIndex, Graph<V> scg)
+    {
+        /*
+         * Find cycles in a strongly connected graph per Johnson.
+         */
+        boolean foundCycle = false;
+        V vertex = toV(vertexIndex);
+        stack.push(vertex);
+        blocked.add(vertex);
+
+        for (V successor : scg.successors(vertex)) {
+            int successorIndex = toI(successor);
+            if (successorIndex == startIndex) {
+                List<V> cycle = new ArrayList<>(stack.size());
+                stack.descendingIterator().forEachRemaining(cycle::add);
+                cycleConsumer.accept(cycle);
+                cycleVertexSuccessorConsumer.accept(vertex, successor); // Paper
+                //foundCycle = true; // Paper
+            } else if (!blocked.contains(successor)) {
+                boolean gotCycle = findCyclesInSCG(startIndex, successorIndex, scg);
+                foundCycle = foundCycle || gotCycle;
+            }
+        }
+        if (foundCycle) {
+            unblock(vertex);
+        } else {
+            for (V w : scg.successors(vertex)) {
+                Set<V> bSet = getBSet(w);
+                bSet.add(vertex);
+            }
+        }
+        stack.pop();
+        return foundCycle;
+    }
+
+    private void unblock(V vertex)
+    {
+        blocked.remove(vertex);
+        Set<V> bSet = getBSet(vertex);
+        while (bSet.size() > 0) {
+            V w = bSet.iterator().next();
+            bSet.remove(w);
+            if (blocked.contains(w)) {
+                unblock(w);
+            }
+        }
+    }
+
+    @SuppressWarnings("unchecked")
+    private void initState(Consumer<List<V>> consumer)
+    {
+        cycleConsumer = consumer;
+        iToV = (V[]) graph.nodes().toArray();
+        vToI = new HashMap<>();
+        blocked = new HashSet<>();
+        bSets = new HashMap<>();
+        stack = new ArrayDeque<>();
+
+        for (int i = 0; i < iToV.length; i++) {
+            vToI.put(iToV[i], i);
+        }
+    }
+
+    private void clearState()
+    {
+        cycleConsumer = null;
+        iToV = null;
+        vToI = null;
+        blocked = null;
+        bSets = null;
+        stack = null;
+    }
+
+    private void initMinSCGState()
+    {
+        index = 0;
+        foundSCCs = new ArrayList<>();
+        vIndex = new HashMap<>();
+        vLowlink = new HashMap<>();
+        path = new ArrayDeque<>();
+        pathSet = new HashSet<>();
+    }
+
+    private void clearMinSCCState()
+    {
+        index = 0;
+        foundSCCs = null;
+        vIndex = null;
+        vLowlink = null;
+        path = null;
+        pathSet = null;
+    }
+
+    private Integer toI(V vertex)
+    {
+        return vToI.get(vertex);
+    }
+
+    private V toV(Integer i)
+    {
+        return iToV[i];
+    }
+
+    private Set<V> getBSet(V v)
+    {
+        // B sets typically not all needed,
+        // so instantiate lazily.
+        return bSets.computeIfAbsent(v, k -> new HashSet<>());
+    }
+}

paper-server/src/main/java/io/papermc/paper/plugin/entrypoint/strategy/LegacyPluginLoadingStrategy.java

@@ -0,0 +1,271 @@
+package io.papermc.paper.plugin.entrypoint.strategy;
+
+import com.google.common.graph.GraphBuilder;
+import com.google.common.graph.MutableGraph;
+import io.papermc.paper.plugin.configuration.PluginMeta;
+import io.papermc.paper.plugin.entrypoint.dependency.GraphDependencyContext;
+import io.papermc.paper.plugin.entrypoint.dependency.MetaDependencyTree;
+import io.papermc.paper.plugin.provider.PluginProvider;
+import io.papermc.paper.plugin.provider.type.paper.PaperPluginParent;
+import org.bukkit.plugin.UnknownDependencyException;
+
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.HashMap;
+import java.util.HashSet;
+import java.util.Iterator;
+import java.util.LinkedList;
+import java.util.List;
+import java.util.Map;
+import java.util.Set;
+import java.util.logging.Level;
+import java.util.logging.Logger;
+
+@SuppressWarnings("UnstableApiUsage")
+public class LegacyPluginLoadingStrategy<T> implements ProviderLoadingStrategy<T> {
+
+    private static final Logger LOGGER = Logger.getLogger("LegacyPluginLoadingStrategy");
+    private final ProviderConfiguration<T> configuration;
+
+    public LegacyPluginLoadingStrategy(ProviderConfiguration<T> onLoad) {
+        this.configuration = onLoad;
+    }
+
+    @Override
+    public List<ProviderPair<T>> loadProviders(List<PluginProvider<T>> providers, MetaDependencyTree dependencyTree) {
+        List<ProviderPair<T>> javapluginsLoaded = new ArrayList<>();
+        MutableGraph<String> dependencyGraph = dependencyTree.getGraph();
+
+        Map<String, PluginProvider<T>> providersToLoad = new HashMap<>();
+        Set<String> loadedPlugins = new HashSet<>();
+        Map<String, String> pluginsProvided = new HashMap<>();
+        Map<String, Collection<String>> dependencies = new HashMap<>();
+        Map<String, Collection<String>> softDependencies = new HashMap<>();
+
+        for (PluginProvider<T> provider : providers) {
+            PluginMeta configuration = provider.getMeta();
+
+            PluginProvider<T> replacedProvider = providersToLoad.put(configuration.getName(), provider);
+            dependencyTree.addDirectDependency(configuration.getName()); // add to dependency tree
+            if (replacedProvider != null) {
+                LOGGER.severe(String.format(
+                    "Ambiguous plugin name `%s' for files `%s' and `%s' in `%s'",
+                    configuration.getName(),
+                    provider.getSource(),
+                    replacedProvider.getSource(),
+                    replacedProvider.getParentSource()
+                ));
+            }
+
+            String removedProvided = pluginsProvided.remove(configuration.getName());
+            if (removedProvided != null) {
+                LOGGER.warning(String.format(
+                    "Ambiguous plugin name `%s'. It is also provided by `%s'",
+                    configuration.getName(),
+                    removedProvided
+                ));
+            }
+
+            for (String provided : configuration.getProvidedPlugins()) {
+                PluginProvider<T> pluginProvider = providersToLoad.get(provided);
+
+                if (pluginProvider != null) {
+                    LOGGER.warning(String.format(
+                        "`%s provides `%s' while this is also the name of `%s' in `%s'",
+                        provider.getSource(),
+                        provided,
+                        pluginProvider.getSource(),
+                        provider.getParentSource()
+                    ));
+                } else {
+                    String replacedPlugin = pluginsProvided.put(provided, configuration.getName());
+                    dependencyTree.addDirectDependency(provided); // add to dependency tree
+                    if (replacedPlugin != null) {
+                        LOGGER.warning(String.format(
+                            "`%s' is provided by both `%s' and `%s'",
+                            provided,
+                            configuration.getName(),
+                            replacedPlugin
+                        ));
+                    }
+                }
+            }
+
+            Collection<String> softDependencySet = provider.getMeta().getPluginSoftDependencies();
+            if (softDependencySet != null && !softDependencySet.isEmpty()) {
+                if (softDependencies.containsKey(configuration.getName())) {
+                    // Duplicates do not matter, they will be removed together if applicable
+                    softDependencies.get(configuration.getName()).addAll(softDependencySet);
+                } else {
+                    softDependencies.put(configuration.getName(), new LinkedList<String>(softDependencySet));
+                }
+
+                for (String depend : softDependencySet) {
+                    dependencyGraph.putEdge(configuration.getName(), depend);
+                }
+            }
+
+            Collection<String> dependencySet = provider.getMeta().getPluginDependencies();
+            if (dependencySet != null && !dependencySet.isEmpty()) {
+                dependencies.put(configuration.getName(), new LinkedList<String>(dependencySet));
+
+                for (String depend : dependencySet) {
+                    dependencyGraph.putEdge(configuration.getName(), depend);
+                }
+            }
+
+            Collection<String> loadBeforeSet = provider.getMeta().getLoadBeforePlugins();
+            if (loadBeforeSet != null && !loadBeforeSet.isEmpty()) {
+                for (String loadBeforeTarget : loadBeforeSet) {
+                    if (softDependencies.containsKey(loadBeforeTarget)) {
+                        softDependencies.get(loadBeforeTarget).add(configuration.getName());
+                    } else {
+                        // softDependencies is never iterated, so 'ghost' plugins aren't an issue
+                        Collection<String> shortSoftDependency = new LinkedList<String>();
+                        shortSoftDependency.add(configuration.getName());
+                        softDependencies.put(loadBeforeTarget, shortSoftDependency);
+                    }
+
+                    dependencyGraph.putEdge(loadBeforeTarget, configuration.getName());
+                }
+            }
+        }
+
+        while (!providersToLoad.isEmpty()) {
+            boolean missingDependency = true;
+            Iterator<Map.Entry<String, PluginProvider<T>>> providerIterator = providersToLoad.entrySet().iterator();
+
+            while (providerIterator.hasNext()) {
+                Map.Entry<String, PluginProvider<T>> entry = providerIterator.next();
+                String providerIdentifier = entry.getKey();
+
+                if (dependencies.containsKey(providerIdentifier)) {
+                    Iterator<String> dependencyIterator = dependencies.get(providerIdentifier).iterator();
+                    final Set<String> missingHardDependencies = new HashSet<>(dependencies.get(providerIdentifier).size()); // Paper - list all missing hard depends
+
+                    while (dependencyIterator.hasNext()) {
+                        String dependency = dependencyIterator.next();
+
+                        // Dependency loaded
+                        if (loadedPlugins.contains(dependency)) {
+                            dependencyIterator.remove();
+
+                            // We have a dependency not found
+                        } else if (!providersToLoad.containsKey(dependency) && !pluginsProvided.containsKey(dependency)) {
+                            // Paper start
+                            missingHardDependencies.add(dependency);
+                        }
+                    }
+                    if (!missingHardDependencies.isEmpty()) {
+                        // Paper end
+                        missingDependency = false;
+                        providerIterator.remove();
+                        pluginsProvided.values().removeIf(s -> s.equals(providerIdentifier)); // Paper - remove provided plugins
+                        softDependencies.remove(providerIdentifier);
+                        dependencies.remove(providerIdentifier);
+
+                        LOGGER.log(
+                            Level.SEVERE,
+                            "Could not load '" + entry.getValue().getSource() + "' in folder '" + entry.getValue().getParentSource() + "'", // Paper
+                            new UnknownDependencyException(missingHardDependencies, providerIdentifier)); // Paper
+                    }
+
+                    if (dependencies.containsKey(providerIdentifier) && dependencies.get(providerIdentifier).isEmpty()) {
+                        dependencies.remove(providerIdentifier);
+                    }
+                }
+                if (softDependencies.containsKey(providerIdentifier)) {
+                    Iterator<String> softDependencyIterator = softDependencies.get(providerIdentifier).iterator();
+
+                    while (softDependencyIterator.hasNext()) {
+                        String softDependency = softDependencyIterator.next();
+
+                        // Soft depend is no longer around
+                        if (!providersToLoad.containsKey(softDependency) && !pluginsProvided.containsKey(softDependency)) {
+                            softDependencyIterator.remove();
+                        }
+                    }
+
+                    if (softDependencies.get(providerIdentifier).isEmpty()) {
+                        softDependencies.remove(providerIdentifier);
+                    }
+                }
+                if (!(dependencies.containsKey(providerIdentifier) || softDependencies.containsKey(providerIdentifier)) && providersToLoad.containsKey(providerIdentifier)) {
+                    // We're clear to load, no more soft or hard dependencies left
+                    PluginProvider<T> file = providersToLoad.get(providerIdentifier);
+                    providerIterator.remove();
+                    pluginsProvided.values().removeIf(s -> s.equals(providerIdentifier)); // Paper - remove provided plugins
+                    missingDependency = false;
+
+                    try {
+                        this.configuration.applyContext(file, dependencyTree);
+                        T loadedPlugin = file.createInstance();
+                        this.warnIfPaperPlugin(file);
+
+                        if (this.configuration.load(file, loadedPlugin)) {
+                            loadedPlugins.add(file.getMeta().getName());
+                            loadedPlugins.addAll(file.getMeta().getProvidedPlugins());
+                            javapluginsLoaded.add(new ProviderPair<>(file, loadedPlugin));
+                        }
+
+                    } catch (Throwable ex) {
+                        LOGGER.log(Level.SEVERE, "Could not load '" + file.getSource() + "' in folder '" + file.getParentSource() + "'", ex); // Paper
+                    }
+                }
+            }
+
+            if (missingDependency) {
+                // We now iterate over plugins until something loads
+                // This loop will ignore soft dependencies
+                providerIterator = providersToLoad.entrySet().iterator();
+
+                while (providerIterator.hasNext()) {
+                    Map.Entry<String, PluginProvider<T>> entry = providerIterator.next();
+                    String plugin = entry.getKey();
+
+                    if (!dependencies.containsKey(plugin)) {
+                        softDependencies.remove(plugin);
+                        missingDependency = false;
+                        PluginProvider<T> file = entry.getValue();
+                        providerIterator.remove();
+
+                        try {
+                            this.configuration.applyContext(file, dependencyTree);
+                            T loadedPlugin = file.createInstance();
+                            this.warnIfPaperPlugin(file);
+
+                            if (this.configuration.load(file, loadedPlugin)) {
+                                loadedPlugins.add(file.getMeta().getName());
+                                loadedPlugins.addAll(file.getMeta().getProvidedPlugins());
+                                javapluginsLoaded.add(new ProviderPair<>(file, loadedPlugin));
+                            }
+                            break;
+                        } catch (Throwable ex) {
+                            LOGGER.log(Level.SEVERE, "Could not load '" + file.getSource() + "' in folder '" + file.getParentSource() + "'", ex); // Paper
+                        }
+                    }
+                }
+                // We have no plugins left without a depend
+                if (missingDependency) {
+                    softDependencies.clear();
+                    dependencies.clear();
+                    Iterator<PluginProvider<T>> failedPluginIterator = providersToLoad.values().iterator();
+
+                    while (failedPluginIterator.hasNext()) {
+                        PluginProvider<T> file = failedPluginIterator.next();
+                        failedPluginIterator.remove();
+                        LOGGER.log(Level.SEVERE, "Could not load '" + file.getSource() + "' in folder '" + file.getParentSource() + "': circular dependency detected"); // Paper
+                    }
+                }
+            }
+        }
+
+        return javapluginsLoaded;
+    }
+
+    private void warnIfPaperPlugin(PluginProvider<T> provider) {
+        if (provider instanceof PaperPluginParent.PaperServerPluginProvider) {
+            provider.getLogger().warn("Loading Paper plugin in the legacy plugin loading logic. This is not recommended and may introduce some differences into load order. It's highly recommended you move away from this if you are wanting to use Paper plugins.");
+        }
+    }
+}

paper-server/src/main/java/io/papermc/paper/plugin/entrypoint/strategy/PluginGraphCycleException.java

@@ -0,0 +1,19 @@
+package io.papermc.paper.plugin.entrypoint.strategy;
+
+import java.util.List;
+
+/**
+ * Indicates a dependency cycle within a provider loading sequence.
+ */
+public class PluginGraphCycleException extends RuntimeException {
+
+    private final List<List<String>> cycles;
+
+    public PluginGraphCycleException(List<List<String>> cycles) {
+        this.cycles = cycles;
+    }
+
+    public List<List<String>> getCycles() {
+        return this.cycles;
+    }
+}

paper-server/src/main/java/io/papermc/paper/plugin/entrypoint/strategy/ProviderConfiguration.java

@@ -0,0 +1,25 @@
+package io.papermc.paper.plugin.entrypoint.strategy;
+
+import io.papermc.paper.plugin.provider.PluginProvider;
+import io.papermc.paper.plugin.provider.entrypoint.DependencyContext;
+
+/**
+ * Used to share code with the modern and legacy plugin load strategy.
+ *
+ * @param <T>
+ */
+public interface ProviderConfiguration<T> {
+
+    void applyContext(PluginProvider<T> provider, DependencyContext dependencyContext);
+
+    boolean load(PluginProvider<T> provider, T provided);
+
+    default boolean preloadProvider(PluginProvider<T> provider) {
+        return true;
+    }
+
+    default void onGenericError(PluginProvider<T> provider) {
+
+    }
+
+}

paper-server/src/main/java/io/papermc/paper/plugin/entrypoint/strategy/ProviderLoadingStrategy.java

@@ -0,0 +1,22 @@
+package io.papermc.paper.plugin.entrypoint.strategy;
+
+import io.papermc.paper.plugin.entrypoint.dependency.MetaDependencyTree;
+import io.papermc.paper.plugin.provider.PluginProvider;
+
+import java.util.List;
+
+/**
+ * Used by a {@link io.papermc.paper.plugin.storage.SimpleProviderStorage} to load plugin providers in a certain order.
+ * <p>
+ * Returns providers loaded.
+ *
+ * @param <P> provider type
+ */
+public interface ProviderLoadingStrategy<P> {
+
+    List<ProviderPair<P>> loadProviders(List<PluginProvider<P>> providers, MetaDependencyTree dependencyTree);
+
+    record ProviderPair<P>(PluginProvider<P> provider, P provided) {
+
+    }
+}

paper-server/src/main/java/io/papermc/paper/plugin/entrypoint/strategy/TopographicGraphSorter.java

@@ -0,0 +1,58 @@
+package io.papermc.paper.plugin.entrypoint.strategy;
+
+import com.google.common.graph.Graph;
+import it.unimi.dsi.fastutil.objects.Object2IntMap;
+import it.unimi.dsi.fastutil.objects.Object2IntOpenHashMap;
+import java.util.ArrayDeque;
+import java.util.ArrayList;
+import java.util.Deque;
+import java.util.List;
+
+public final class TopographicGraphSorter {
+
+    // Topographically sort dependencies
+    public static <N> List<N> sortGraph(Graph<N> graph) throws PluginGraphCycleException {
+        List<N> sorted = new ArrayList<>();
+        Deque<N> roots = new ArrayDeque<>();
+        Object2IntMap<N> nonRoots = new Object2IntOpenHashMap<>();
+
+        for (N node : graph.nodes()) {
+            // Is a node being referred to by any other nodes?
+            int degree = graph.inDegree(node);
+            if (degree == 0) {
+                // Is a root
+                roots.add(node);
+            } else {
+                // Isn't a root, the number represents how many nodes connect to it.
+                nonRoots.put(node, degree);
+            }
+        }
+
+        // Pick from nodes that aren't referred to anywhere else
+        N next;
+        while ((next = roots.poll()) != null) {
+            for (N successor : graph.successors(next)) {
+                // Traverse through, moving down a degree
+                int newInDegree = nonRoots.removeInt(successor) - 1;
+
+                if (newInDegree == 0) {
+                    roots.add(successor);
+                } else {
+                    nonRoots.put(successor, newInDegree);
+                }
+
+            }
+            sorted.add(next);
+        }
+
+        if (!nonRoots.isEmpty()) {
+            throw new GraphCycleException();
+        }
+
+        return sorted;
+    }
+
+    public static final class GraphCycleException extends RuntimeException {
+
+    }
+}

paper-server/src/main/java/io/papermc/paper/plugin/entrypoint/strategy/modern/LoadOrderTree.java

@@ -0,0 +1,121 @@
+package io.papermc.paper.plugin.entrypoint.strategy.modern;
+
+import com.google.common.collect.Lists;
+import com.google.common.graph.MutableGraph;
+import com.mojang.logging.LogUtils;
+import io.papermc.paper.plugin.configuration.PluginMeta;
+import io.papermc.paper.plugin.entrypoint.strategy.JohnsonSimpleCycles;
+import io.papermc.paper.plugin.entrypoint.strategy.PluginGraphCycleException;
+import io.papermc.paper.plugin.entrypoint.strategy.TopographicGraphSorter;
+import io.papermc.paper.plugin.provider.PluginProvider;
+import io.papermc.paper.plugin.provider.configuration.LoadOrderConfiguration;
+import io.papermc.paper.plugin.provider.configuration.PaperPluginMeta;
+import io.papermc.paper.plugin.provider.type.spigot.SpigotPluginProvider;
+import org.slf4j.Logger;
+
+import java.util.ArrayList;
+import java.util.HashSet;
+import java.util.List;
+import java.util.Map;
+import java.util.Set;
+
+class LoadOrderTree {
+
+    private static final Logger LOGGER = LogUtils.getClassLogger();
+
+    private final Map<String, PluginProvider<?>> providerMap;
+    private final MutableGraph<String> graph;
+
+    public LoadOrderTree(Map<String, PluginProvider<?>> providerMapMirror, MutableGraph<String> graph) {
+        this.providerMap = providerMapMirror;
+        this.graph = graph;
+    }
+
+    public void add(PluginProvider<?> provider) {
+        LoadOrderConfiguration configuration = provider.createConfiguration(this.providerMap);
+
+        // Build a validated provider's load order changes
+        String identifier = configuration.getMeta().getName();
+        for (String dependency : configuration.getLoadAfter()) {
+            if (this.providerMap.containsKey(dependency)) {
+                this.graph.putEdge(identifier, dependency);
+            }
+        }
+
+        for (String loadBeforeTarget : configuration.getLoadBefore()) {
+            if (this.providerMap.containsKey(loadBeforeTarget)) {
+                this.graph.putEdge(loadBeforeTarget, identifier);
+            }
+        }
+
+        this.graph.addNode(identifier); // Make sure load order has at least one node
+    }
+
+    public List<String> getLoadOrder() throws PluginGraphCycleException {
+        List<String> reversedTopographicSort;
+        try {
+            reversedTopographicSort = Lists.reverse(TopographicGraphSorter.sortGraph(this.graph));
+        } catch (TopographicGraphSorter.GraphCycleException exception) {
+            List<List<String>> cycles = new JohnsonSimpleCycles<>(this.graph).findAndRemoveSimpleCycles();
+
+            // Only log an error if at least non-Spigot plugin is present in the cycle
+            // Due to Spigot plugin metadata making no distinction between load order and dependencies (= class loader access), cycles are an unfortunate reality we have to deal with
+            Set<String> cyclingPlugins = new HashSet<>();
+            cycles.forEach(cyclingPlugins::addAll);
+            if (cyclingPlugins.stream().anyMatch(plugin -> {
+                PluginProvider<?> pluginProvider = this.providerMap.get(plugin);
+                return pluginProvider != null && !(pluginProvider instanceof SpigotPluginProvider);
+            })) {
+                logCycleError(cycles, this.providerMap);
+            }
+
+            // Try again after hopefully having removed all cycles
+            try {
+                reversedTopographicSort = Lists.reverse(TopographicGraphSorter.sortGraph(this.graph));
+            } catch (TopographicGraphSorter.GraphCycleException e) {
+                throw new PluginGraphCycleException(cycles);
+            }
+        }
+
+        return reversedTopographicSort;
+    }
+
+    private void logCycleError(List<List<String>> cycles, Map<String, PluginProvider<?>> providerMapMirror) {
+        LOGGER.error("=================================");
+        LOGGER.error("Circular plugin loading detected:");
+        for (int i = 0; i < cycles.size(); i++) {
+            List<String> cycle = cycles.get(i);
+            LOGGER.error("{}) {} -> {}", i + 1, String.join(" -> ", cycle), cycle.get(0));
+            for (String pluginName : cycle) {
+                PluginProvider<?> pluginProvider = providerMapMirror.get(pluginName);
+                if (pluginProvider == null) {
+                    return;
+                }
+
+                logPluginInfo(pluginProvider.getMeta());
+            }
+        }
+
+        LOGGER.error("Please report this to the plugin authors of the first plugin of each loop or join the PaperMC Discord server for further help.");
+        LOGGER.error("=================================");
+    }
+
+    private void logPluginInfo(PluginMeta meta) {
+        if (!meta.getLoadBeforePlugins().isEmpty()) {
+            LOGGER.error("   {} loadbefore: {}", meta.getName(), meta.getLoadBeforePlugins());
+        }
+
+        if (meta instanceof PaperPluginMeta paperPluginMeta) {
+            if (!paperPluginMeta.getLoadAfterPlugins().isEmpty()) {
+                LOGGER.error("   {} loadafter: {}", meta.getName(), paperPluginMeta.getLoadAfterPlugins());
+            }
+        } else {
+            List<String> dependencies = new ArrayList<>();
+            dependencies.addAll(meta.getPluginDependencies());
+            dependencies.addAll(meta.getPluginSoftDependencies());
+            if (!dependencies.isEmpty()) {
+                LOGGER.error("   {} depend/softdepend: {}", meta.getName(), dependencies);
+            }
+        }
+    }
+}

paper-server/src/main/java/io/papermc/paper/plugin/entrypoint/strategy/modern/ModernPluginLoadingStrategy.java

@@ -0,0 +1,138 @@
+package io.papermc.paper.plugin.entrypoint.strategy.modern;
+
+import com.google.common.collect.Maps;
+import com.google.common.graph.GraphBuilder;
+import com.mojang.logging.LogUtils;
+import io.papermc.paper.plugin.configuration.PluginMeta;
+import io.papermc.paper.plugin.entrypoint.dependency.GraphDependencyContext;
+import io.papermc.paper.plugin.entrypoint.dependency.MetaDependencyTree;
+import io.papermc.paper.plugin.entrypoint.strategy.ProviderConfiguration;
+import io.papermc.paper.plugin.entrypoint.strategy.ProviderLoadingStrategy;
+import io.papermc.paper.plugin.provider.PluginProvider;
+import org.bukkit.plugin.UnknownDependencyException;
+import org.slf4j.Logger;
+
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.HashSet;
+import java.util.List;
+import java.util.Map;
+
+@SuppressWarnings("UnstableApiUsage")
+public class ModernPluginLoadingStrategy<T> implements ProviderLoadingStrategy<T> {
+
+    private static final Logger LOGGER = LogUtils.getClassLogger();
+    private final ProviderConfiguration<T> configuration;
+
+    public ModernPluginLoadingStrategy(ProviderConfiguration<T> onLoad) {
+        this.configuration = onLoad;
+    }
+
+    @Override
+    public List<ProviderPair<T>> loadProviders(List<PluginProvider<T>> pluginProviders, MetaDependencyTree dependencyTree) {
+        Map<String, PluginProviderEntry<T>> providerMap = new HashMap<>();
+        Map<String, PluginProvider<?>> providerMapMirror = Maps.transformValues(providerMap, (entry) -> entry.provider);
+        List<PluginProvider<T>> validatedProviders = new ArrayList<>();
+
+        // Populate provider map
+        for (PluginProvider<T> provider : pluginProviders) {
+            PluginMeta providerConfig = provider.getMeta();
+            PluginProviderEntry<T> entry = new PluginProviderEntry<>(provider);
+
+            PluginProviderEntry<T> replacedProvider = providerMap.put(providerConfig.getName(), entry);
+            if (replacedProvider != null) {
+                LOGGER.error(String.format(
+                    "Ambiguous plugin name '%s' for files '%s' and '%s' in '%s'",
+                    providerConfig.getName(),
+                    provider.getSource(),
+                    replacedProvider.provider.getSource(),
+                    replacedProvider.provider.getParentSource()
+                ));
+                this.configuration.onGenericError(replacedProvider.provider);
+            }
+
+            for (String extra : providerConfig.getProvidedPlugins()) {
+                PluginProviderEntry<T> replacedExtraProvider = providerMap.putIfAbsent(extra, entry);
+                if (replacedExtraProvider != null) {
+                    LOGGER.warn(String.format(
+                        "`%s' is provided by both `%s' and `%s'",
+                        extra,
+                        providerConfig.getName(),
+                        replacedExtraProvider.provider.getMeta().getName()
+                    ));
+                }
+            }
+        }
+
+        // Populate dependency tree
+        for (PluginProvider<?> validated : pluginProviders) {
+            dependencyTree.add(validated);
+        }
+
+        // Validate providers, ensuring all of them have valid dependencies. Removing those who are invalid
+        for (PluginProvider<T> provider : pluginProviders) {
+            PluginMeta configuration = provider.getMeta();
+
+            // Populate missing dependencies to capture if there are multiple missing ones.
+            List<String> missingDependencies = provider.validateDependencies(dependencyTree);
+
+            if (missingDependencies.isEmpty()) {
+                validatedProviders.add(provider);
+            } else {
+                LOGGER.error("Could not load '%s' in '%s'".formatted(provider.getSource(), provider.getParentSource()), new UnknownDependencyException(missingDependencies, configuration.getName())); // Paper
+                // Because the validator is invalid, remove it from the provider map
+                providerMap.remove(configuration.getName());
+                // Cleanup plugins that failed to load
+                dependencyTree.remove(provider);
+                this.configuration.onGenericError(provider);
+            }
+        }
+
+        LoadOrderTree loadOrderTree = new LoadOrderTree(providerMapMirror, GraphBuilder.directed().build());
+        // Populate load order tree
+        for (PluginProvider<?> validated : validatedProviders) {
+            loadOrderTree.add(validated);
+        }
+
+        // Reverse the topographic search to let us see which providers we can load first.
+        List<String> reversedTopographicSort = loadOrderTree.getLoadOrder();
+        List<ProviderPair<T>> loadedPlugins = new ArrayList<>();
+        for (String providerIdentifier : reversedTopographicSort) {
+            // It's possible that this will be null because the above dependencies for soft/load before aren't validated if they exist.
+            // The graph could be MutableGraph<PluginProvider<T>>, but we would have to check if each dependency exists there... just
+            // nicer to do it here TBH.
+            PluginProviderEntry<T> retrievedProviderEntry = providerMap.get(providerIdentifier);
+            if (retrievedProviderEntry == null || retrievedProviderEntry.provided) {
+                // OR if this was already provided (most likely from a plugin that already "provides" that dependency)
+                // This won't matter since the provided plugin is loaded as a dependency, meaning it should have been loaded correctly anyways
+                continue; // Skip provider that doesn't exist....
+            }
+            retrievedProviderEntry.provided = true;
+            PluginProvider<T> retrievedProvider = retrievedProviderEntry.provider;
+            try {
+                this.configuration.applyContext(retrievedProvider, dependencyTree);
+
+                if (this.configuration.preloadProvider(retrievedProvider)) {
+                    T instance = retrievedProvider.createInstance();
+                    if (this.configuration.load(retrievedProvider, instance)) {
+                        loadedPlugins.add(new ProviderPair<>(retrievedProvider, instance));
+                    }
+                }
+            } catch (Throwable ex) {
+                LOGGER.error("Could not load plugin '%s' in folder '%s'".formatted(retrievedProvider.getFileName(), retrievedProvider.getParentSource()), ex); // Paper
+            }
+        }
+
+        return loadedPlugins;
+    }
+
+    private static class PluginProviderEntry<T> {
+
+        private final PluginProvider<T> provider;
+        private boolean provided;
+
+        private PluginProviderEntry(PluginProvider<T> provider) {
+            this.provider = provider;
+        }
+    }
+}

paper-server/src/main/java/io/papermc/paper/plugin/loader/PaperClasspathBuilder.java

@@ -0,0 +1,64 @@
+package io.papermc.paper.plugin.loader;
+
+import io.papermc.paper.plugin.bootstrap.PluginProviderContext;
+import io.papermc.paper.plugin.loader.library.ClassPathLibrary;
+import io.papermc.paper.plugin.loader.library.PaperLibraryStore;
+import io.papermc.paper.plugin.entrypoint.classloader.PaperPluginClassLoader;
+import io.papermc.paper.plugin.provider.configuration.PaperPluginMeta;
+import org.jetbrains.annotations.NotNull;
+
+import java.io.IOException;
+import java.net.MalformedURLException;
+import java.net.URL;
+import java.net.URLClassLoader;
+import java.nio.file.Path;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.jar.JarFile;
+import java.util.logging.Logger;
+
+public class PaperClasspathBuilder implements PluginClasspathBuilder {
+
+    private final List<ClassPathLibrary> libraries = new ArrayList<>();
+
+    private final PluginProviderContext context;
+
+    public PaperClasspathBuilder(PluginProviderContext context) {
+        this.context = context;
+    }
+
+    @Override
+    public @NotNull PluginProviderContext getContext() {
+        return this.context;
+    }
+
+    @Override
+    public @NotNull PluginClasspathBuilder addLibrary(@NotNull ClassPathLibrary classPathLibrary) {
+        this.libraries.add(classPathLibrary);
+        return this;
+    }
+
+    public PaperPluginClassLoader buildClassLoader(Logger logger, Path source, JarFile jarFile, PaperPluginMeta configuration) {
+        PaperLibraryStore paperLibraryStore = new PaperLibraryStore();
+        for (ClassPathLibrary library : this.libraries) {
+            library.register(paperLibraryStore);
+        }
+
+        List<Path> paths = paperLibraryStore.getPaths();
+        URL[] urls = new URL[paths.size()];
+        for (int i = 0; i < paths.size(); i++) {
+            Path path = paperLibraryStore.getPaths().get(i);
+            try {
+                urls[i] = path.toUri().toURL();
+            } catch (MalformedURLException e) {
+                throw new AssertionError(e);
+            }
+        }
+
+        try {
+            return new PaperPluginClassLoader(logger, source, jarFile, configuration, this.getClass().getClassLoader(), new URLClassLoader(urls, getClass().getClassLoader()));
+        } catch (IOException exception) {
+            throw new RuntimeException(exception);
+        }
+    }
+}

paper-server/src/main/java/io/papermc/paper/plugin/loader/library/PaperLibraryStore.java

@@ -0,0 +1,21 @@
+package io.papermc.paper.plugin.loader.library;
+
+import org.jetbrains.annotations.NotNull;
+
+import java.nio.file.Path;
+import java.util.ArrayList;
+import java.util.List;
+
+public class PaperLibraryStore implements LibraryStore {
+
+    private final List<Path> paths = new ArrayList<>();
+
+    @Override
+    public void addLibrary(@NotNull Path library) {
+        this.paths.add(library);
+    }
+
+    public List<Path> getPaths() {
+        return this.paths;
+    }
+}

paper-server/src/main/java/io/papermc/paper/plugin/manager/DummyBukkitPluginLoader.java

@@ -0,0 +1,82 @@
+package io.papermc.paper.plugin.manager;
+
+import io.papermc.paper.plugin.configuration.PluginMeta;
+import io.papermc.paper.plugin.provider.type.PluginFileType;
+import org.bukkit.Bukkit;
+import org.bukkit.event.Event;
+import org.bukkit.event.Listener;
+import org.bukkit.plugin.InvalidDescriptionException;
+import org.bukkit.plugin.InvalidPluginException;
+import org.bukkit.plugin.Plugin;
+import org.bukkit.plugin.PluginDescriptionFile;
+import org.bukkit.plugin.PluginLoader;
+import org.bukkit.plugin.RegisteredListener;
+import org.bukkit.plugin.UnknownDependencyException;
+import org.jetbrains.annotations.ApiStatus;
+import org.jetbrains.annotations.NotNull;
+
+import java.io.File;
+import java.io.FileNotFoundException;
+import java.io.IOException;
+import java.util.Map;
+import java.util.Set;
+import java.util.jar.JarFile;
+import java.util.regex.Pattern;
+
+/**
+ * A purely internal type that implements the now deprecated {@link PluginLoader} after the implementation
+ * of papers new plugin system.
+ */
+@ApiStatus.Internal
+public class DummyBukkitPluginLoader implements PluginLoader {
+
+    private static final Pattern[] PATTERNS = new Pattern[0];
+
+    @Override
+    public @NotNull Plugin loadPlugin(@NotNull File file) throws InvalidPluginException, UnknownDependencyException {
+        try {
+            return PaperPluginManagerImpl.getInstance().loadPlugin(file);
+        } catch (InvalidDescriptionException e) {
+            throw new InvalidPluginException(e);
+        }
+    }
+
+    @Override
+    public @NotNull PluginDescriptionFile getPluginDescription(@NotNull File file) throws InvalidDescriptionException {
+        try (JarFile jar = new JarFile(file)) {
+            PluginFileType<?, ?> type = PluginFileType.guessType(jar);
+            if (type == null) {
+                throw new InvalidDescriptionException(new FileNotFoundException("Jar does not contain plugin.yml"));
+            }
+
+            PluginMeta meta = type.getConfig(jar);
+            if (meta instanceof PluginDescriptionFile pluginDescriptionFile) {
+                return pluginDescriptionFile;
+            } else {
+                throw new InvalidDescriptionException("Plugin type does not use plugin.yml. Cannot read file description.");
+            }
+        } catch (Exception e) {
+            throw new InvalidDescriptionException(e);
+        }
+    }
+
+    @Override
+    public @NotNull Pattern[] getPluginFileFilters() {
+        return PATTERNS;
+    }
+
+    @Override
+    public @NotNull Map<Class<? extends Event>, Set<RegisteredListener>> createRegisteredListeners(@NotNull Listener listener, @NotNull Plugin plugin) {
+        return PaperPluginManagerImpl.getInstance().paperEventManager.createRegisteredListeners(listener, plugin);
+    }
+
+    @Override
+    public void enablePlugin(@NotNull Plugin plugin) {
+        Bukkit.getPluginManager().enablePlugin(plugin);
+    }
+
+    @Override
+    public void disablePlugin(@NotNull Plugin plugin) {
+        Bukkit.getPluginManager().disablePlugin(plugin);
+    }
+}

paper-server/src/main/java/io/papermc/paper/plugin/manager/MultiRuntimePluginProviderStorage.java

@@ -0,0 +1,61 @@
+package io.papermc.paper.plugin.manager;
+
+import com.mojang.logging.LogUtils;
+import io.papermc.paper.plugin.entrypoint.Entrypoint;
+import io.papermc.paper.plugin.entrypoint.LaunchEntryPointHandler;
+import io.papermc.paper.plugin.entrypoint.dependency.GraphDependencyContext;
+import io.papermc.paper.plugin.entrypoint.dependency.MetaDependencyTree;
+import io.papermc.paper.plugin.provider.PluginProvider;
+import io.papermc.paper.plugin.provider.type.paper.PaperPluginParent;
+import io.papermc.paper.plugin.storage.ServerPluginProviderStorage;
+import org.bukkit.plugin.java.JavaPlugin;
+import org.slf4j.Logger;
+
+import java.util.ArrayList;
+import java.util.List;
+
+public class MultiRuntimePluginProviderStorage extends ServerPluginProviderStorage {
+
+    private static final Logger LOGGER = LogUtils.getClassLogger();
+    private final List<JavaPlugin> provided = new ArrayList<>();
+
+    private final MetaDependencyTree dependencyTree;
+
+    MultiRuntimePluginProviderStorage(MetaDependencyTree dependencyTree) {
+        this.dependencyTree = dependencyTree;
+    }
+
+    @Override
+    public void register(PluginProvider<JavaPlugin> provider) {
+        if (provider instanceof PaperPluginParent.PaperServerPluginProvider) {
+            LOGGER.warn("Skipping loading of paper plugin requested from SimplePluginManager.");
+            return;
+        }
+        super.register(provider);
+        /*
+        Register the provider into the server entrypoint, this allows it to show in /plugins correctly. Generally it might be better in the future to make a separate storage,
+         as putting it into the entrypoint handlers doesn't make much sense.
+         */
+        LaunchEntryPointHandler.INSTANCE.register(Entrypoint.PLUGIN, provider);
+    }
+
+    @Override
+    public void processProvided(PluginProvider<JavaPlugin> provider, JavaPlugin provided) {
+        super.processProvided(provider, provided);
+        this.provided.add(provided);
+    }
+
+    @Override
+    public boolean throwOnCycle() {
+        return false;
+    }
+
+    public List<JavaPlugin> getLoaded() {
+        return this.provided;
+    }
+
+    @Override
+    public MetaDependencyTree createDependencyTree() {
+        return this.dependencyTree;
+    }
+}

paper-server/src/main/java/io/papermc/paper/plugin/manager/NormalPaperPermissionManager.java

@@ -0,0 +1,43 @@
+package io.papermc.paper.plugin.manager;
+
+import org.bukkit.permissions.Permissible;
+import org.bukkit.permissions.Permission;
+
+import java.util.HashMap;
+import java.util.LinkedHashMap;
+import java.util.LinkedHashSet;
+import java.util.Map;
+import java.util.Set;
+
+class NormalPaperPermissionManager extends PaperPermissionManager {
+
+    private final Map<String, Permission> permissions = new HashMap<>();
+    private final Map<Boolean, Set<Permission>> defaultPerms = new LinkedHashMap<>();
+    private final Map<String, Map<Permissible, Boolean>> permSubs = new HashMap<>();
+    private final Map<Boolean, Map<Permissible, Boolean>> defSubs = new HashMap<>();
+
+    public NormalPaperPermissionManager() {
+        this.defaultPerms().put(true, new LinkedHashSet<>());
+        this.defaultPerms().put(false, new LinkedHashSet<>());
+    }
+
+    @Override
+    public Map<String, Permission> permissions() {
+        return this.permissions;
+    }
+
+    @Override
+    public Map<Boolean, Set<Permission>> defaultPerms() {
+        return this.defaultPerms;
+    }
+
+    @Override
+    public Map<String, Map<Permissible, Boolean>> permSubs() {
+        return this.permSubs;
+    }
+
+    @Override
+    public Map<Boolean, Map<Permissible, Boolean>> defSubs() {
+        return this.defSubs;
+    }
+}

paper-server/src/main/java/io/papermc/paper/plugin/manager/PaperEventManager.java

@@ -0,0 +1,194 @@
+package io.papermc.paper.plugin.manager;
+
+import co.aikar.timings.TimedEventExecutor;
+import com.destroystokyo.paper.event.server.ServerExceptionEvent;
+import com.destroystokyo.paper.exception.ServerEventException;
+import com.google.common.collect.Sets;
+import org.bukkit.Server;
+import org.bukkit.Warning;
+import org.bukkit.event.Event;
+import org.bukkit.event.EventHandler;
+import org.bukkit.event.EventPriority;
+import org.bukkit.event.HandlerList;
+import org.bukkit.event.Listener;
+import org.bukkit.plugin.AuthorNagException;
+import org.bukkit.plugin.EventExecutor;
+import org.bukkit.plugin.IllegalPluginAccessException;
+import org.bukkit.plugin.Plugin;
+import org.bukkit.plugin.RegisteredListener;
+import org.jetbrains.annotations.NotNull;
+
+import java.lang.reflect.Method;
+import java.util.Arrays;
+import java.util.HashMap;
+import java.util.HashSet;
+import java.util.Map;
+import java.util.Set;
+import java.util.logging.Level;
+
+class PaperEventManager {
+
+    private final Server server;
+
+    public PaperEventManager(Server server) {
+        this.server = server;
+    }
+
+    // SimplePluginManager
+    public void callEvent(@NotNull Event event) {
+        if (event.isAsynchronous() && this.server.isPrimaryThread()) {
+            throw new IllegalStateException(event.getEventName() + " may only be triggered asynchronously.");
+        } else if (!event.isAsynchronous() && !this.server.isPrimaryThread() && !this.server.isStopping()) {
+            throw new IllegalStateException(event.getEventName() + " may only be triggered synchronously.");
+        }
+
+        HandlerList handlers = event.getHandlers();
+        RegisteredListener[] listeners = handlers.getRegisteredListeners();
+
+        for (RegisteredListener registration : listeners) {
+            if (!registration.getPlugin().isEnabled()) {
+                continue;
+            }
+
+            try {
+                registration.callEvent(event);
+            } catch (AuthorNagException ex) {
+                Plugin plugin = registration.getPlugin();
+
+                if (plugin.isNaggable()) {
+                    plugin.setNaggable(false);
+
+                    this.server.getLogger().log(Level.SEVERE, String.format(
+                        "Nag author(s): '%s' of '%s' about the following: %s",
+                        plugin.getPluginMeta().getAuthors(),
+                        plugin.getPluginMeta().getDisplayName(),
+                        ex.getMessage()
+                    ));
+                }
+            } catch (Throwable ex) {
+                String msg = "Could not pass event " + event.getEventName() + " to " + registration.getPlugin().getPluginMeta().getDisplayName();
+                this.server.getLogger().log(Level.SEVERE, msg, ex);
+                if (!(event instanceof ServerExceptionEvent)) { // We don't want to cause an endless event loop
+                    this.callEvent(new ServerExceptionEvent(new ServerEventException(msg, ex, registration.getPlugin(), registration.getListener(), event)));
+                }
+            }
+        }
+    }
+
+    public void registerEvents(@NotNull Listener listener, @NotNull Plugin plugin) {
+        if (!plugin.isEnabled()) {
+            throw new IllegalPluginAccessException("Plugin attempted to register " + listener + " while not enabled");
+        }
+
+        for (Map.Entry<Class<? extends Event>, Set<RegisteredListener>> entry : this.createRegisteredListeners(listener, plugin).entrySet()) {
+            this.getEventListeners(this.getRegistrationClass(entry.getKey())).registerAll(entry.getValue());
+        }
+
+    }
+
+    public void registerEvent(@NotNull Class<? extends Event> event, @NotNull Listener listener, @NotNull EventPriority priority, @NotNull EventExecutor executor, @NotNull Plugin plugin) {
+        this.registerEvent(event, listener, priority, executor, plugin, false);
+    }
+
+    public void registerEvent(@NotNull Class<? extends Event> event, @NotNull Listener listener, @NotNull EventPriority priority, @NotNull EventExecutor executor, @NotNull Plugin plugin, boolean ignoreCancelled) {
+        if (!plugin.isEnabled()) {
+            throw new IllegalPluginAccessException("Plugin attempted to register " + event + " while not enabled");
+        }
+
+        executor = new TimedEventExecutor(executor, plugin, null, event);
+        this.getEventListeners(event).register(new RegisteredListener(listener, executor, priority, plugin, ignoreCancelled));
+    }
+
+    @NotNull
+    private HandlerList getEventListeners(@NotNull Class<? extends Event> type) {
+        try {
+            Method method = this.getRegistrationClass(type).getDeclaredMethod("getHandlerList");
+            method.setAccessible(true);
+            return (HandlerList) method.invoke(null);
+        } catch (Exception e) {
+            throw new IllegalPluginAccessException(e.toString());
+        }
+    }
+
+    @NotNull
+    private Class<? extends Event> getRegistrationClass(@NotNull Class<? extends Event> clazz) {
+        try {
+            clazz.getDeclaredMethod("getHandlerList");
+            return clazz;
+        } catch (NoSuchMethodException e) {
+            if (clazz.getSuperclass() != null
+                && !clazz.getSuperclass().equals(Event.class)
+                && Event.class.isAssignableFrom(clazz.getSuperclass())) {
+                return this.getRegistrationClass(clazz.getSuperclass().asSubclass(Event.class));
+            } else {
+                throw new IllegalPluginAccessException("Unable to find handler list for event " + clazz.getName() + ". Static getHandlerList method required!");
+            }
+        }
+    }
+
+    // JavaPluginLoader
+    @NotNull
+    public Map<Class<? extends Event>, Set<RegisteredListener>> createRegisteredListeners(@NotNull Listener listener, @NotNull final Plugin plugin) {
+        Map<Class<? extends Event>, Set<RegisteredListener>> ret = new HashMap<>();
+
+        Set<Method> methods;
+        try {
+            Class<?> listenerClazz = listener.getClass();
+            methods = Sets.union(
+                Set.of(listenerClazz.getMethods()),
+                Set.of(listenerClazz.getDeclaredMethods())
+            );
+        } catch (NoClassDefFoundError e) {
+            plugin.getLogger().severe("Failed to register events for " + listener.getClass() + " because " + e.getMessage() + " does not exist.");
+            return ret;
+        }
+
+        for (final Method method : methods) {
+            final EventHandler eh = method.getAnnotation(EventHandler.class);
+            if (eh == null) continue;
+            // Do not register bridge or synthetic methods to avoid event duplication
+            // Fixes SPIGOT-893
+            if (method.isBridge() || method.isSynthetic()) {
+                continue;
+            }
+            final Class<?> checkClass;
+            if (method.getParameterTypes().length != 1 || !Event.class.isAssignableFrom(checkClass = method.getParameterTypes()[0])) {
+                plugin.getLogger().severe(plugin.getPluginMeta().getDisplayName() + " attempted to register an invalid EventHandler method signature \"" + method.toGenericString() + "\" in " + listener.getClass());
+                continue;
+            }
+            final Class<? extends Event> eventClass = checkClass.asSubclass(Event.class);
+            method.setAccessible(true);
+            Set<RegisteredListener> eventSet = ret.computeIfAbsent(eventClass, k -> new HashSet<>());
+
+            for (Class<?> clazz = eventClass; Event.class.isAssignableFrom(clazz); clazz = clazz.getSuperclass()) {
+                // This loop checks for extending deprecated events
+                if (clazz.getAnnotation(Deprecated.class) != null) {
+                    Warning warning = clazz.getAnnotation(Warning.class);
+                    Warning.WarningState warningState = this.server.getWarningState();
+                    if (!warningState.printFor(warning)) {
+                        break;
+                    }
+                    plugin.getLogger().log(
+                        Level.WARNING,
+                        String.format(
+                            "\"%s\" has registered a listener for %s on method \"%s\", but the event is Deprecated. \"%s\"; please notify the authors %s.",
+                            plugin.getPluginMeta().getDisplayName(),
+                            clazz.getName(),
+                            method.toGenericString(),
+                            (warning != null && warning.reason().length() != 0) ? warning.reason() : "Server performance will be affected",
+                            Arrays.toString(plugin.getPluginMeta().getAuthors().toArray())),
+                        warningState == Warning.WarningState.ON ? new AuthorNagException(null) : null);
+                    break;
+                }
+            }
+
+            EventExecutor executor = new TimedEventExecutor(EventExecutor.create(method, eventClass), plugin, method, eventClass);
+            eventSet.add(new RegisteredListener(listener, executor, eh.priority(), plugin, eh.ignoreCancelled()));
+        }
+        return ret;
+    }
+
+    public void clearEvents() {
+        HandlerList.unregisterAll();
+    }
+}

paper-server/src/main/java/io/papermc/paper/plugin/manager/PaperPermissionManager.java

@@ -0,0 +1,201 @@
+package io.papermc.paper.plugin.manager;
+
+import com.google.common.collect.ImmutableSet;
+import io.papermc.paper.plugin.PermissionManager;
+import org.bukkit.permissions.Permissible;
+import org.bukkit.permissions.Permission;
+import org.bukkit.permissions.PermissionDefault;
+import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
+
+import java.util.HashSet;
+import java.util.List;
+import java.util.Locale;
+import java.util.Map;
+import java.util.Set;
+import java.util.WeakHashMap;
+
+/**
+ * See
+ * {@link StupidSPMPermissionManagerWrapper}
+ */
+abstract class PaperPermissionManager implements PermissionManager {
+
+    public abstract Map<String, Permission> permissions();
+
+    public abstract Map<Boolean, Set<Permission>> defaultPerms();
+
+    public abstract Map<String, Map<Permissible, Boolean>> permSubs();
+
+    public abstract Map<Boolean, Map<Permissible, Boolean>> defSubs();
+
+    @Override
+    @Nullable
+    public Permission getPermission(@NotNull String name) {
+        return this.permissions().get(name.toLowerCase(java.util.Locale.ENGLISH));
+    }
+
+    @Override
+    public void addPermission(@NotNull Permission perm) {
+        this.addPermission(perm, true);
+    }
+
+    @Override
+    public void addPermissions(@NotNull List<Permission> permissions) {
+        for (Permission permission : permissions) {
+            this.addPermission(permission, false);
+        }
+        this.dirtyPermissibles();
+    }
+
+    // Allow suppressing permission default calculations
+    private void addPermission(@NotNull Permission perm, boolean dirty) {
+        String name = perm.getName().toLowerCase(java.util.Locale.ENGLISH);
+
+        if (this.permissions().containsKey(name)) {
+            throw new IllegalArgumentException("The permission " + name + " is already defined!");
+        }
+
+        this.permissions().put(name, perm);
+        this.calculatePermissionDefault(perm, dirty);
+    }
+
+    @Override
+    @NotNull
+    public Set<Permission> getDefaultPermissions(boolean op) {
+        return ImmutableSet.copyOf(this.defaultPerms().get(op));
+    }
+
+
+    @Override
+    public void removePermission(@NotNull Permission perm) {
+        this.removePermission(perm.getName());
+    }
+
+
+    @Override
+    public void removePermission(@NotNull String name) {
+        this.permissions().remove(name.toLowerCase(java.util.Locale.ENGLISH));
+    }
+
+    @Override
+    public void recalculatePermissionDefaults(@NotNull Permission perm) {
+        // we need a null check here because some plugins for some unknown reason pass null into this?
+        if (perm != null && this.permissions().containsKey(perm.getName().toLowerCase(Locale.ROOT))) {
+            this.defaultPerms().get(true).remove(perm);
+            this.defaultPerms().get(false).remove(perm);
+
+            this.calculatePermissionDefault(perm, true);
+        }
+    }
+
+    private void calculatePermissionDefault(@NotNull Permission perm, boolean dirty) {
+        if ((perm.getDefault() == PermissionDefault.OP) || (perm.getDefault() == PermissionDefault.TRUE)) {
+            this.defaultPerms().get(true).add(perm);
+            if (dirty) {
+                this.dirtyPermissibles(true);
+            }
+        }
+        if ((perm.getDefault() == PermissionDefault.NOT_OP) || (perm.getDefault() == PermissionDefault.TRUE)) {
+            this.defaultPerms().get(false).add(perm);
+            if (dirty) {
+                this.dirtyPermissibles(false);
+            }
+        }
+    }
+
+
+    @Override
+    public void subscribeToPermission(@NotNull String permission, @NotNull Permissible permissible) {
+        String name = permission.toLowerCase(java.util.Locale.ENGLISH);
+        Map<Permissible, Boolean> map = this.permSubs().computeIfAbsent(name, k -> new WeakHashMap<>());
+
+        map.put(permissible, true);
+    }
+
+    @Override
+    public void unsubscribeFromPermission(@NotNull String permission, @NotNull Permissible permissible) {
+        String name = permission.toLowerCase(java.util.Locale.ENGLISH);
+        Map<Permissible, Boolean> map = this.permSubs().get(name);
+
+        if (map != null) {
+            map.remove(permissible);
+
+            if (map.isEmpty()) {
+                this.permSubs().remove(name);
+            }
+        }
+    }
+
+    @Override
+    @NotNull
+    public Set<Permissible> getPermissionSubscriptions(@NotNull String permission) {
+        String name = permission.toLowerCase(java.util.Locale.ENGLISH);
+        Map<Permissible, Boolean> map = this.permSubs().get(name);
+
+        if (map == null) {
+            return ImmutableSet.of();
+        } else {
+            return ImmutableSet.copyOf(map.keySet());
+        }
+    }
+
+    @Override
+    public void subscribeToDefaultPerms(boolean op, @NotNull Permissible permissible) {
+        Map<Permissible, Boolean> map = this.defSubs().computeIfAbsent(op, k -> new WeakHashMap<>());
+
+        map.put(permissible, true);
+    }
+
+    @Override
+    public void unsubscribeFromDefaultPerms(boolean op, @NotNull Permissible permissible) {
+        Map<Permissible, Boolean> map = this.defSubs().get(op);
+
+        if (map != null) {
+            map.remove(permissible);
+
+            if (map.isEmpty()) {
+                this.defSubs().remove(op);
+            }
+        }
+    }
+
+    @Override
+    @NotNull
+    public Set<Permissible> getDefaultPermSubscriptions(boolean op) {
+        Map<Permissible, Boolean> map = this.defSubs().get(op);
+
+        if (map == null) {
+            return ImmutableSet.of();
+        } else {
+            return ImmutableSet.copyOf(map.keySet());
+        }
+    }
+
+    @Override
+    @NotNull
+    public Set<Permission> getPermissions() {
+        return new HashSet<>(this.permissions().values());
+    }
+
+    @Override
+    public void clearPermissions() {
+        this.permissions().clear();
+        this.defaultPerms().get(true).clear();
+        this.defaultPerms().get(false).clear();
+    }
+
+
+    void dirtyPermissibles(boolean op) {
+        Set<Permissible> permissibles = this.getDefaultPermSubscriptions(op);
+
+        for (Permissible p : permissibles) {
+            p.recalculatePermissions();
+        }
+    }
+
+    void dirtyPermissibles() {
+        this.dirtyPermissibles(true);
+        this.dirtyPermissibles(false);
+    }
+}

paper-server/src/main/java/io/papermc/paper/plugin/manager/PaperPluginInstanceManager.java

@@ -0,0 +1,317 @@
+package io.papermc.paper.plugin.manager;
+
+import com.google.common.base.Preconditions;
+import com.google.common.graph.GraphBuilder;
+import com.google.common.graph.MutableGraph;
+import io.papermc.paper.plugin.configuration.PluginMeta;
+import io.papermc.paper.plugin.entrypoint.Entrypoint;
+import io.papermc.paper.plugin.entrypoint.dependency.MetaDependencyTree;
+import io.papermc.paper.plugin.entrypoint.dependency.SimpleMetaDependencyTree;
+import io.papermc.paper.plugin.entrypoint.strategy.PluginGraphCycleException;
+import io.papermc.paper.plugin.provider.classloader.ConfiguredPluginClassLoader;
+import io.papermc.paper.plugin.provider.classloader.PaperClassLoaderStorage;
+import io.papermc.paper.plugin.provider.source.DirectoryProviderSource;
+import io.papermc.paper.plugin.provider.source.FileArrayProviderSource;
+import io.papermc.paper.plugin.provider.source.FileProviderSource;
+import java.io.File;
+import org.bukkit.Bukkit;
+import org.bukkit.Server;
+import org.bukkit.World;
+import org.bukkit.command.Command;
+import org.bukkit.command.CommandMap;
+import org.bukkit.command.PluginCommandYamlParser;
+import org.bukkit.craftbukkit.util.CraftMagicNumbers;
+import org.bukkit.event.HandlerList;
+import org.bukkit.event.server.PluginDisableEvent;
+import org.bukkit.event.server.PluginEnableEvent;
+import org.bukkit.plugin.InvalidPluginException;
+import org.bukkit.plugin.Plugin;
+import org.bukkit.plugin.PluginDescriptionFile;
+import org.bukkit.plugin.PluginManager;
+import org.bukkit.plugin.UnknownDependencyException;
+import org.bukkit.plugin.java.JavaPlugin;
+import org.jetbrains.annotations.ApiStatus;
+import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
+
+import java.io.IOException;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.logging.Level;
+
+@SuppressWarnings("UnstableApiUsage")
+class PaperPluginInstanceManager {
+
+    private static final FileProviderSource FILE_PROVIDER_SOURCE = new FileProviderSource("File '%s'"::formatted);
+
+    private final List<Plugin> plugins = new ArrayList<>();
+    private final Map<String, Plugin> lookupNames = new HashMap<>();
+
+    private final PluginManager pluginManager;
+    private final CommandMap commandMap;
+    private final Server server;
+
+    private final MetaDependencyTree dependencyTree = new SimpleMetaDependencyTree(GraphBuilder.directed().build());
+
+    public PaperPluginInstanceManager(PluginManager pluginManager, CommandMap commandMap, Server server) {
+        this.commandMap = commandMap;
+        this.server = server;
+        this.pluginManager = pluginManager;
+    }
+
+    public @Nullable Plugin getPlugin(@NotNull String name) {
+        return this.lookupNames.get(name.replace(' ', '_').toLowerCase(java.util.Locale.ENGLISH)); // Paper
+    }
+
+    public @NotNull Plugin[] getPlugins() {
+        return this.plugins.toArray(new Plugin[0]);
+    }
+
+    public boolean isPluginEnabled(@NotNull String name) {
+        Plugin plugin = this.getPlugin(name);
+
+        return this.isPluginEnabled(plugin);
+    }
+
+    public synchronized boolean isPluginEnabled(@Nullable Plugin plugin) {
+        if ((plugin != null) && (this.plugins.contains(plugin))) {
+            return plugin.isEnabled();
+        } else {
+            return false;
+        }
+    }
+
+    public void loadPlugin(Plugin provided) {
+        PluginMeta configuration = provided.getPluginMeta();
+
+        this.plugins.add(provided);
+        this.lookupNames.put(configuration.getName().toLowerCase(java.util.Locale.ENGLISH), provided);
+        for (String providedPlugin : configuration.getProvidedPlugins()) {
+            this.lookupNames.putIfAbsent(providedPlugin.toLowerCase(java.util.Locale.ENGLISH), provided);
+        }
+
+        this.dependencyTree.add(configuration);
+    }
+
+    // InvalidDescriptionException is never used, because the old JavaPluginLoader would wrap the exception.
+    public @Nullable Plugin loadPlugin(@NotNull Path path) throws InvalidPluginException, UnknownDependencyException {
+        RuntimePluginEntrypointHandler<SingularRuntimePluginProviderStorage> runtimePluginEntrypointHandler = new RuntimePluginEntrypointHandler<>(new SingularRuntimePluginProviderStorage(this.dependencyTree));
+
+        try {
+            path = FILE_PROVIDER_SOURCE.prepareContext(path);
+            FILE_PROVIDER_SOURCE.registerProviders(runtimePluginEntrypointHandler, path);
+        } catch (IllegalArgumentException exception) {
+            return null; // Return null when the plugin file is not valid / plugin type is unknown
+        } catch (PluginGraphCycleException exception) {
+            throw new InvalidPluginException("Cannot import plugin that causes cyclic dependencies!");
+        } catch (Exception e) {
+            throw new InvalidPluginException(e);
+        }
+
+        try {
+            runtimePluginEntrypointHandler.enter(Entrypoint.PLUGIN);
+        } catch (Throwable e) {
+            throw new InvalidPluginException(e);
+        }
+
+        return runtimePluginEntrypointHandler.getPluginProviderStorage().getSingleLoaded()
+            .orElseThrow(() -> new InvalidPluginException("Plugin didn't load any plugin providers?"));
+    }
+
+    public @NotNull Plugin[] loadPlugins(@NotNull File[] files) {
+        RuntimePluginEntrypointHandler<MultiRuntimePluginProviderStorage> runtimePluginEntrypointHandler = new RuntimePluginEntrypointHandler<>(new MultiRuntimePluginProviderStorage(this.dependencyTree));
+        try {
+            List<Path> paths = FileArrayProviderSource.INSTANCE.prepareContext(files);
+            DirectoryProviderSource.INSTANCE.registerProviders(runtimePluginEntrypointHandler, paths);
+            runtimePluginEntrypointHandler.enter(Entrypoint.PLUGIN);
+        } catch (Exception e) {
+            // This should never happen, any errors that occur in this provider should instead be logged.
+            this.server.getLogger().log(Level.SEVERE, "Unknown error occurred while loading plugins through PluginManager.", e);
+        }
+
+        return runtimePluginEntrypointHandler.getPluginProviderStorage().getLoaded().toArray(new JavaPlugin[0]);
+    }
+
+    // The behavior of this is that all errors are logged instead of being thrown
+    public @NotNull Plugin[] loadPlugins(@NotNull Path directory) {
+        Preconditions.checkArgument(Files.isDirectory(directory), "Directory must be a directory"); // Avoid creating a directory if it doesn't exist
+
+        RuntimePluginEntrypointHandler<MultiRuntimePluginProviderStorage> runtimePluginEntrypointHandler = new RuntimePluginEntrypointHandler<>(new MultiRuntimePluginProviderStorage(this.dependencyTree));
+        try {
+            List<Path> files = DirectoryProviderSource.INSTANCE.prepareContext(directory);
+            DirectoryProviderSource.INSTANCE.registerProviders(runtimePluginEntrypointHandler, files);
+            runtimePluginEntrypointHandler.enter(Entrypoint.PLUGIN);
+        } catch (Exception e) {
+            // This should never happen, any errors that occur in this provider should instead be logged.
+            this.server.getLogger().log(Level.SEVERE, "Unknown error occurred while loading plugins through PluginManager.", e);
+        }
+
+        return runtimePluginEntrypointHandler.getPluginProviderStorage().getLoaded().toArray(new JavaPlugin[0]);
+    }
+
+    // Plugins are disabled in order like this inorder to "rougly" prevent
+    // their dependencies unloading first. But, eh.
+    public void disablePlugins() {
+        Plugin[] plugins = this.getPlugins();
+        for (int i = plugins.length - 1; i >= 0; i--) {
+            this.disablePlugin(plugins[i]);
+        }
+    }
+
+    public void clearPlugins() {
+        synchronized (this) {
+            this.disablePlugins();
+            this.plugins.clear();
+            this.lookupNames.clear();
+        }
+    }
+
+    public synchronized void enablePlugin(@NotNull Plugin plugin) {
+        if (plugin.isEnabled()) {
+            return;
+        }
+
+        if (plugin.getPluginMeta() instanceof PluginDescriptionFile) {
+            List<Command> bukkitCommands = PluginCommandYamlParser.parse(plugin);
+
+            if (!bukkitCommands.isEmpty()) {
+                this.commandMap.registerAll(plugin.getPluginMeta().getName(), bukkitCommands);
+            }
+        }
+
+        try {
+            String enableMsg = "Enabling " + plugin.getPluginMeta().getDisplayName();
+            if (plugin.getPluginMeta() instanceof PluginDescriptionFile descriptionFile && CraftMagicNumbers.isLegacy(descriptionFile)) {
+                enableMsg += "*";
+            }
+            plugin.getLogger().info(enableMsg);
+
+            JavaPlugin jPlugin = (JavaPlugin) plugin;
+
+            if (jPlugin.getClass().getClassLoader() instanceof ConfiguredPluginClassLoader classLoader) { // Paper
+                if (PaperClassLoaderStorage.instance().registerUnsafePlugin(classLoader)) {
+                    this.server.getLogger().log(Level.WARNING, "Enabled plugin with unregistered ConfiguredPluginClassLoader " + plugin.getPluginMeta().getDisplayName());
+                }
+            } // Paper
+
+            try {
+                jPlugin.setEnabled(true);
+            } catch (Throwable ex) {
+                this.server.getLogger().log(Level.SEVERE, "Error occurred while enabling " + plugin.getPluginMeta().getDisplayName() + " (Is it up to date?)", ex);
+                // Paper start - Disable plugins that fail to load
+                this.server.getPluginManager().disablePlugin(jPlugin);
+                return;
+                // Paper end
+            }
+
+            // Perhaps abort here, rather than continue going, but as it stands,
+            // an abort is not possible the way it's currently written
+            this.server.getPluginManager().callEvent(new PluginEnableEvent(plugin));
+        } catch (Throwable ex) {
+            this.handlePluginException("Error occurred (in the plugin loader) while enabling "
+                + plugin.getPluginMeta().getDisplayName() + " (Is it up to date?)", ex, plugin);
+        }
+
+        HandlerList.bakeAll();
+    }
+
+    public synchronized void disablePlugin(@NotNull Plugin plugin) {
+        if (!(plugin instanceof JavaPlugin javaPlugin)) {
+            throw new IllegalArgumentException("Only expects java plugins.");
+        }
+        if (!plugin.isEnabled()) {
+            return;
+        }
+
+        String pluginName = plugin.getPluginMeta().getDisplayName();
+
+        try {
+            plugin.getLogger().info("Disabling %s".formatted(pluginName));
+
+            this.server.getPluginManager().callEvent(new PluginDisableEvent(plugin));
+            try {
+                javaPlugin.setEnabled(false);
+            } catch (Throwable ex) {
+                this.server.getLogger().log(Level.SEVERE, "Error occurred while disabling " + pluginName, ex);
+            }
+
+            ClassLoader classLoader = plugin.getClass().getClassLoader();
+            if (classLoader instanceof ConfiguredPluginClassLoader configuredPluginClassLoader) {
+                try {
+                    configuredPluginClassLoader.close();
+                } catch (IOException ex) {
+                    this.server.getLogger().log(Level.WARNING, "Error closing the classloader for '" + pluginName + "'", ex); // Paper - log exception
+                }
+                // Remove from the classloader pool inorder to prevent plugins from trying
+                // to access classes
+                PaperClassLoaderStorage.instance().unregisterClassloader(configuredPluginClassLoader);
+            }
+
+        } catch (Throwable ex) {
+            this.handlePluginException("Error occurred (in the plugin loader) while disabling "
+                + pluginName + " (Is it up to date?)", ex, plugin); // Paper
+        }
+
+        try {
+            this.server.getScheduler().cancelTasks(plugin);
+        } catch (Throwable ex) {
+            this.handlePluginException("Error occurred (in the plugin loader) while cancelling tasks for "
+                + pluginName + " (Is it up to date?)", ex, plugin); // Paper
+        }
+
+        try {
+            this.server.getServicesManager().unregisterAll(plugin);
+        } catch (Throwable ex) {
+            this.handlePluginException("Error occurred (in the plugin loader) while unregistering services for "
+                + pluginName + " (Is it up to date?)", ex, plugin); // Paper
+        }
+
+        try {
+            HandlerList.unregisterAll(plugin);
+        } catch (Throwable ex) {
+            this.handlePluginException("Error occurred (in the plugin loader) while unregistering events for "
+                + pluginName + " (Is it up to date?)", ex, plugin); // Paper
+        }
+
+        try {
+            this.server.getMessenger().unregisterIncomingPluginChannel(plugin);
+            this.server.getMessenger().unregisterOutgoingPluginChannel(plugin);
+        } catch (Throwable ex) {
+            this.handlePluginException("Error occurred (in the plugin loader) while unregistering plugin channels for "
+                + pluginName + " (Is it up to date?)", ex, plugin); // Paper
+        }
+
+        try {
+            for (World world : this.server.getWorlds()) {
+                world.removePluginChunkTickets(plugin);
+            }
+        } catch (Throwable ex) {
+            this.handlePluginException("Error occurred (in the plugin loader) while removing chunk tickets for " + pluginName + " (Is it up to date?)", ex, plugin); // Paper
+        }
+
+    }
+
+    // TODO: Implement event part in future patch (paper patch move up, this patch is lower)
+    private void handlePluginException(String msg, Throwable ex, Plugin plugin) {
+        Bukkit.getServer().getLogger().log(Level.SEVERE, msg, ex);
+        this.pluginManager.callEvent(new com.destroystokyo.paper.event.server.ServerExceptionEvent(new com.destroystokyo.paper.exception.ServerPluginEnableDisableException(msg, ex, plugin)));
+    }
+
+    public boolean isTransitiveDepend(@NotNull PluginMeta plugin, @NotNull PluginMeta depend) {
+        return this.dependencyTree.isTransitiveDependency(plugin, depend);
+    }
+
+    public boolean hasDependency(String pluginIdentifier) {
+        return this.getPlugin(pluginIdentifier) != null;
+    }
+
+    // Debug only
+    @ApiStatus.Internal
+    public MutableGraph<String> getDependencyGraph() {
+        return this.dependencyTree.getGraph();
+    }
+}

paper-server/src/main/java/io/papermc/paper/plugin/manager/PaperPluginManagerImpl.java

@@ -0,0 +1,246 @@
+package io.papermc.paper.plugin.manager;
+
+import com.google.common.graph.MutableGraph;
+import io.papermc.paper.plugin.PermissionManager;
+import io.papermc.paper.plugin.configuration.PluginMeta;
+import io.papermc.paper.plugin.provider.entrypoint.DependencyContext;
+import org.bukkit.Bukkit;
+import org.bukkit.Server;
+import org.bukkit.command.CommandMap;
+import org.bukkit.craftbukkit.CraftServer;
+import org.bukkit.event.Event;
+import org.bukkit.event.EventPriority;
+import org.bukkit.event.Listener;
+import org.bukkit.permissions.Permissible;
+import org.bukkit.permissions.Permission;
+import org.bukkit.plugin.EventExecutor;
+import org.bukkit.plugin.InvalidDescriptionException;
+import org.bukkit.plugin.InvalidPluginException;
+import org.bukkit.plugin.Plugin;
+import org.bukkit.plugin.PluginLoader;
+import org.bukkit.plugin.PluginManager;
+import org.bukkit.plugin.SimplePluginManager;
+import org.bukkit.plugin.UnknownDependencyException;
+import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
+
+import java.io.File;
+import java.util.List;
+import java.util.Set;
+
+public class PaperPluginManagerImpl implements PluginManager, DependencyContext {
+
+    final PaperPluginInstanceManager instanceManager;
+    final PaperEventManager paperEventManager;
+    PermissionManager permissionManager;
+
+    public PaperPluginManagerImpl(Server server, CommandMap commandMap, @Nullable SimplePluginManager permissionManager) {
+        this.instanceManager = new PaperPluginInstanceManager(this, commandMap, server);
+        this.paperEventManager = new PaperEventManager(server);
+
+        if (permissionManager == null) {
+            this.permissionManager = new NormalPaperPermissionManager();
+        } else {
+            this.permissionManager = new StupidSPMPermissionManagerWrapper(permissionManager); // TODO: See comment when SimplePermissionManager is removed
+        }
+    }
+
+    // REMOVE THIS WHEN SimplePluginManager is removed.
+    // Just cast and use Bukkit.getServer().getPluginManager()
+    public static PaperPluginManagerImpl getInstance() {
+        return ((CraftServer) (Bukkit.getServer())).paperPluginManager;
+    }
+
+    // Plugin Manipulation
+
+    @Override
+    public @Nullable Plugin getPlugin(@NotNull String name) {
+        return this.instanceManager.getPlugin(name);
+    }
+
+    @Override
+    public @NotNull Plugin[] getPlugins() {
+        return this.instanceManager.getPlugins();
+    }
+
+    @Override
+    public boolean isPluginEnabled(@NotNull String name) {
+        return this.instanceManager.isPluginEnabled(name);
+    }
+
+    @Override
+    public boolean isPluginEnabled(@Nullable Plugin plugin) {
+        return this.instanceManager.isPluginEnabled(plugin);
+    }
+
+    public void loadPlugin(Plugin plugin) {
+        this.instanceManager.loadPlugin(plugin);
+    }
+
+    @Override
+    public @Nullable Plugin loadPlugin(@NotNull File file) throws InvalidPluginException, InvalidDescriptionException, UnknownDependencyException {
+        return this.instanceManager.loadPlugin(file.toPath());
+    }
+
+    @Override
+    public @NotNull Plugin[] loadPlugins(@NotNull File directory) {
+        return this.instanceManager.loadPlugins(directory.toPath());
+    }
+
+    @Override
+    public @NotNull Plugin[] loadPlugins(final @NotNull File[] files) {
+        return this.instanceManager.loadPlugins(files);
+    }
+
+    @Override
+    public void disablePlugins() {
+        this.instanceManager.disablePlugins();
+    }
+
+    @Override
+    public synchronized void clearPlugins() {
+        this.instanceManager.clearPlugins();
+        this.permissionManager.clearPermissions();
+        this.paperEventManager.clearEvents();
+    }
+
+    @Override
+    public void enablePlugin(@NotNull Plugin plugin) {
+        this.instanceManager.enablePlugin(plugin);
+    }
+
+    @Override
+    public void disablePlugin(@NotNull Plugin plugin) {
+        this.instanceManager.disablePlugin(plugin);
+    }
+
+    @Override
+    public boolean isTransitiveDependency(PluginMeta pluginMeta, PluginMeta dependencyConfig) {
+        return this.instanceManager.isTransitiveDepend(pluginMeta, dependencyConfig);
+    }
+
+    @Override
+    public boolean hasDependency(String pluginIdentifier) {
+        return this.instanceManager.hasDependency(pluginIdentifier);
+    }
+
+    // Event manipulation
+
+    @Override
+    public void callEvent(@NotNull Event event) throws IllegalStateException {
+        this.paperEventManager.callEvent(event);
+    }
+
+    @Override
+    public void registerEvents(@NotNull Listener listener, @NotNull Plugin plugin) {
+        this.paperEventManager.registerEvents(listener, plugin);
+    }
+
+    @Override
+    public void registerEvent(@NotNull Class<? extends Event> event, @NotNull Listener listener, @NotNull EventPriority priority, @NotNull EventExecutor executor, @NotNull Plugin plugin) {
+        this.paperEventManager.registerEvent(event, listener, priority, executor, plugin);
+    }
+
+    @Override
+    public void registerEvent(@NotNull Class<? extends Event> event, @NotNull Listener listener, @NotNull EventPriority priority, @NotNull EventExecutor executor, @NotNull Plugin plugin, boolean ignoreCancelled) {
+        this.paperEventManager.registerEvent(event, listener, priority, executor, plugin, ignoreCancelled);
+    }
+
+    // Permission manipulation
+
+    @Override
+    public @Nullable Permission getPermission(@NotNull String name) {
+        return this.permissionManager.getPermission(name);
+    }
+
+    @Override
+    public void addPermission(@NotNull Permission perm) {
+        this.permissionManager.addPermission(perm);
+    }
+
+    @Override
+    public void removePermission(@NotNull Permission perm) {
+        this.permissionManager.removePermission(perm);
+    }
+
+    @Override
+    public void removePermission(@NotNull String name) {
+        this.permissionManager.removePermission(name);
+    }
+
+    @Override
+    public @NotNull Set<Permission> getDefaultPermissions(boolean op) {
+        return this.permissionManager.getDefaultPermissions(op);
+    }
+
+    @Override
+    public void recalculatePermissionDefaults(@NotNull Permission perm) {
+        this.permissionManager.recalculatePermissionDefaults(perm);
+    }
+
+    @Override
+    public void subscribeToPermission(@NotNull String permission, @NotNull Permissible permissible) {
+        this.permissionManager.subscribeToPermission(permission, permissible);
+    }
+
+    @Override
+    public void unsubscribeFromPermission(@NotNull String permission, @NotNull Permissible permissible) {
+        this.permissionManager.unsubscribeFromPermission(permission, permissible);
+    }
+
+    @Override
+    public @NotNull Set<Permissible> getPermissionSubscriptions(@NotNull String permission) {
+        return this.permissionManager.getPermissionSubscriptions(permission);
+    }
+
+    @Override
+    public void subscribeToDefaultPerms(boolean op, @NotNull Permissible permissible) {
+        this.permissionManager.subscribeToDefaultPerms(op, permissible);
+    }
+
+    @Override
+    public void unsubscribeFromDefaultPerms(boolean op, @NotNull Permissible permissible) {
+        this.permissionManager.unsubscribeFromDefaultPerms(op, permissible);
+    }
+
+    @Override
+    public @NotNull Set<Permissible> getDefaultPermSubscriptions(boolean op) {
+        return this.permissionManager.getDefaultPermSubscriptions(op);
+    }
+
+    @Override
+    public @NotNull Set<Permission> getPermissions() {
+        return this.permissionManager.getPermissions();
+    }
+
+    @Override
+    public void addPermissions(@NotNull List<Permission> perm) {
+        this.permissionManager.addPermissions(perm);
+    }
+
+    @Override
+    public void clearPermissions() {
+        this.permissionManager.clearPermissions();
+    }
+
+    @Override
+    public void overridePermissionManager(@NotNull Plugin plugin, @Nullable PermissionManager permissionManager) {
+        this.permissionManager = permissionManager;
+    }
+
+    // Etc
+
+    @Override
+    public boolean useTimings() {
+        return co.aikar.timings.Timings.isTimingsEnabled();
+    }
+
+    @Override
+    public void registerInterface(@NotNull Class<? extends PluginLoader> loader) throws IllegalArgumentException {
+        throw new UnsupportedOperationException();
+    }
+
+    public MutableGraph<String> getInstanceManagerGraph() {
+        return instanceManager.getDependencyGraph();
+    }
+}

paper-server/src/main/java/io/papermc/paper/plugin/manager/RuntimePluginEntrypointHandler.java

@@ -0,0 +1,47 @@
+package io.papermc.paper.plugin.manager;
+
+import com.destroystokyo.paper.util.SneakyThrow;
+import io.papermc.paper.plugin.entrypoint.Entrypoint;
+import io.papermc.paper.plugin.entrypoint.EntrypointHandler;
+import io.papermc.paper.plugin.provider.PluginProvider;
+import io.papermc.paper.plugin.storage.ProviderStorage;
+import org.bukkit.plugin.InvalidPluginException;
+import org.bukkit.plugin.java.JavaPlugin;
+import org.jetbrains.annotations.NotNull;
+
+/**
+ * Used for loading plugins during runtime, only supporting providers that are plugins.
+ * This is only used for the plugin manager, as it only allows plugins to be
+ * registered to a provider storage.
+ */
+class RuntimePluginEntrypointHandler<T extends ProviderStorage<JavaPlugin>> implements EntrypointHandler {
+
+    private final T providerStorage;
+
+    RuntimePluginEntrypointHandler(T providerStorage) {
+        this.providerStorage = providerStorage;
+    }
+
+    @Override
+    public <T> void register(Entrypoint<T> entrypoint, PluginProvider<T> provider) {
+        if (!entrypoint.equals(Entrypoint.PLUGIN)) {
+            SneakyThrow.sneaky(new InvalidPluginException("Plugin cannot register entrypoints other than PLUGIN during runtime. Tried registering %s!".formatted(entrypoint)));
+            // We have to throw an invalid plugin exception for legacy reasons
+        }
+
+        this.providerStorage.register((PluginProvider<JavaPlugin>) provider);
+    }
+
+    @Override
+    public void enter(Entrypoint<?> entrypoint) {
+        if (entrypoint != Entrypoint.PLUGIN) {
+            throw new IllegalArgumentException("Only plugin entrypoint supported");
+        }
+        this.providerStorage.enter();
+    }
+
+    @NotNull
+    public T getPluginProviderStorage() {
+        return this.providerStorage;
+    }
+}

paper-server/src/main/java/io/papermc/paper/plugin/manager/SingularRuntimePluginProviderStorage.java

@@ -0,0 +1,79 @@
+package io.papermc.paper.plugin.manager;
+
+import com.destroystokyo.paper.util.SneakyThrow;
+import io.papermc.paper.plugin.entrypoint.Entrypoint;
+import io.papermc.paper.plugin.entrypoint.LaunchEntryPointHandler;
+import io.papermc.paper.plugin.entrypoint.dependency.GraphDependencyContext;
+import io.papermc.paper.plugin.entrypoint.dependency.MetaDependencyTree;
+import io.papermc.paper.plugin.provider.PluginProvider;
+import io.papermc.paper.plugin.provider.type.paper.PaperPluginParent;
+import io.papermc.paper.plugin.storage.ServerPluginProviderStorage;
+import org.bukkit.plugin.InvalidPluginException;
+import org.bukkit.plugin.PluginDescriptionFile;
+import org.bukkit.plugin.UnknownDependencyException;
+import org.bukkit.plugin.java.JavaPlugin;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Optional;
+
+/**
+ * Used for registering a single plugin provider.
+ * This has special behavior in that some errors are thrown instead of logged.
+ */
+class SingularRuntimePluginProviderStorage extends ServerPluginProviderStorage {
+
+    private final MetaDependencyTree dependencyTree;
+    private PluginProvider<JavaPlugin> lastProvider;
+    private JavaPlugin singleLoaded;
+
+    SingularRuntimePluginProviderStorage(MetaDependencyTree dependencyTree) {
+        this.dependencyTree = dependencyTree;
+    }
+
+    @Override
+    public void register(PluginProvider<JavaPlugin> provider) {
+        super.register(provider);
+        if (this.lastProvider != null) {
+            SneakyThrow.sneaky(new InvalidPluginException("Plugin registered two JavaPlugins"));
+        }
+        if (provider instanceof PaperPluginParent.PaperServerPluginProvider) {
+            throw new IllegalStateException("Cannot register paper plugins during runtime!");
+        }
+        this.lastProvider = provider;
+        // Register the provider into the server entrypoint, this allows it to show in /plugins correctly.
+        // Generally it might be better in the future to make a separate storage, as putting it into the entrypoint handlers doesn't make much sense.
+        LaunchEntryPointHandler.INSTANCE.register(Entrypoint.PLUGIN, provider);
+    }
+
+    @Override
+    public void enter() {
+        PluginProvider<JavaPlugin> provider = this.lastProvider;
+        if (provider == null) {
+            return;
+        }
+
+        // Go through normal plugin loading logic
+        super.enter();
+    }
+
+    @Override
+    public void processProvided(PluginProvider<JavaPlugin> provider, JavaPlugin provided) {
+        super.processProvided(provider, provided);
+        this.singleLoaded = provided;
+    }
+
+    @Override
+    public boolean throwOnCycle() {
+        return false;
+    }
+
+    public Optional<JavaPlugin> getSingleLoaded() {
+        return Optional.ofNullable(this.singleLoaded);
+    }
+
+    @Override
+    public MetaDependencyTree createDependencyTree() {
+        return this.dependencyTree;
+    }
+}

paper-server/src/main/java/io/papermc/paper/plugin/manager/StupidSPMPermissionManagerWrapper.java

@@ -0,0 +1,42 @@
+package io.papermc.paper.plugin.manager;
+
+import org.bukkit.permissions.Permissible;
+import org.bukkit.permissions.Permission;
+import org.bukkit.plugin.SimplePluginManager;
+
+import java.util.Map;
+import java.util.Set;
+
+/*
+This is actually so cursed I hate it.
+We need to wrap these in fields as people override the fields, so we need to access them lazily at all times.
+// TODO: When SimplePluginManager is GONE remove this and cleanup the PaperPermissionManager to use actual fields.
+ */
+class StupidSPMPermissionManagerWrapper extends PaperPermissionManager {
+
+    private final SimplePluginManager simplePluginManager;
+
+    public StupidSPMPermissionManagerWrapper(SimplePluginManager simplePluginManager) {
+        this.simplePluginManager = simplePluginManager;
+    }
+
+    @Override
+    public Map<String, Permission> permissions() {
+        return this.simplePluginManager.permissions;
+    }
+
+    @Override
+    public Map<Boolean, Set<Permission>> defaultPerms() {
+        return this.simplePluginManager.defaultPerms;
+    }
+
+    @Override
+    public Map<String, Map<Permissible, Boolean>> permSubs() {
+        return this.simplePluginManager.permSubs;
+    }
+
+    @Override
+    public Map<Boolean, Map<Permissible, Boolean>> defSubs() {
+        return this.simplePluginManager.defSubs;
+    }
+}

paper-server/src/main/java/io/papermc/paper/plugin/provider/PluginProvider.java

@@ -0,0 +1,56 @@
+package io.papermc.paper.plugin.provider;
+
+import io.papermc.paper.plugin.configuration.PluginMeta;
+import io.papermc.paper.plugin.provider.configuration.LoadOrderConfiguration;
+import io.papermc.paper.plugin.provider.entrypoint.DependencyContext;
+import net.kyori.adventure.text.logger.slf4j.ComponentLogger;
+import org.jetbrains.annotations.ApiStatus;
+import org.jetbrains.annotations.NotNull;
+
+import java.nio.file.Path;
+import java.util.List;
+import java.util.Map;
+import java.util.jar.JarFile;
+
+/**
+ * PluginProviders are created by a {@link io.papermc.paper.plugin.provider.source.ProviderSource},
+ * which is loaded into an {@link io.papermc.paper.plugin.entrypoint.EntrypointHandler}.
+ * <p>
+ * A PluginProvider is responsible for providing part of a plugin, whether it's a Bootstrapper or Server Plugin.
+ * The point of this class is to be able to create the actual instance later, as at the time this is created the server
+ * may be missing some key parts. For example, the Bukkit singleton will not be initialized yet, therefor we need to
+ * have a PluginServerProvider load the server plugin later.
+ * <p>
+ * Plugin providers are currently not exposed in any way of the api. It is preferred that this stays this way,
+ * as providers are only needed for initialization.
+ *
+ * @param <T> provider type
+ */
+@ApiStatus.Internal
+public interface PluginProvider<T> {
+
+    @NotNull
+    Path getSource();
+
+    default Path getFileName() {
+        return this.getSource().getFileName();
+    }
+
+    default Path getParentSource() {
+        return this.getSource().getParent();
+    }
+
+    JarFile file();
+
+    T createInstance();
+
+    PluginMeta getMeta();
+
+    ComponentLogger getLogger();
+
+    LoadOrderConfiguration createConfiguration(@NotNull Map<String, PluginProvider<?>> toLoad);
+
+    // Returns a list of missing dependencies
+    List<String> validateDependencies(@NotNull DependencyContext context);
+
+}

paper-server/src/main/java/io/papermc/paper/plugin/provider/ProviderStatus.java

@@ -0,0 +1,13 @@
+package io.papermc.paper.plugin.provider;
+
+import org.jetbrains.annotations.ApiStatus;
+
+/**
+ * This is used for the /plugins command, where it will look in the {@link io.papermc.paper.plugin.entrypoint.LaunchEntryPointHandler} and
+ * use the provider statuses to determine the color.
+ */
+@ApiStatus.Internal
+public enum ProviderStatus {
+    INITIALIZED,
+    ERRORED,
+}

paper-server/src/main/java/io/papermc/paper/plugin/provider/ProviderStatusHolder.java

@@ -0,0 +1,11 @@
+package io.papermc.paper.plugin.provider;
+
+/**
+ * This is used to mark that a plugin provider is able to hold a status for the /plugins command.
+ */
+public interface ProviderStatusHolder {
+
+    ProviderStatus getLastProvidedStatus();
+
+    void setStatus(ProviderStatus status);
+}

paper-server/src/main/java/io/papermc/paper/plugin/provider/configuration/FlattenedResolver.java

@@ -0,0 +1,29 @@
+package io.papermc.paper.plugin.provider.configuration;
+
+import org.checkerframework.checker.nullness.qual.Nullable;
+import org.spongepowered.configurate.objectmapping.meta.NodeResolver;
+
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+import java.lang.reflect.AnnotatedElement;
+
+@Retention(RetentionPolicy.RUNTIME)
+@Target(ElementType.FIELD)
+public @interface FlattenedResolver {
+
+    final class Factory implements NodeResolver.Factory {
+
+        @Override
+        public @Nullable NodeResolver make(String name, AnnotatedElement element) {
+            if (element.isAnnotationPresent(FlattenedResolver.class)) {
+                return (node) -> node;
+            } else {
+                return null;
+            }
+        }
+    }
+
+
+}

paper-server/src/main/java/io/papermc/paper/plugin/provider/configuration/LegacyPaperMeta.java

@@ -0,0 +1,147 @@
+package io.papermc.paper.plugin.provider.configuration;
+
+import com.google.gson.reflect.TypeToken;
+import io.papermc.paper.plugin.provider.configuration.type.DependencyConfiguration;
+import io.papermc.paper.plugin.provider.configuration.type.PluginDependencyLifeCycle;
+import org.spongepowered.configurate.CommentedConfigurationNode;
+import org.spongepowered.configurate.ConfigurateException;
+import org.spongepowered.configurate.NodePath;
+import org.spongepowered.configurate.objectmapping.ConfigSerializable;
+import org.spongepowered.configurate.objectmapping.meta.Required;
+import org.spongepowered.configurate.serialize.SerializationException;
+import org.spongepowered.configurate.transformation.ConfigurationTransformation;
+
+import java.util.EnumMap;
+import java.util.EnumSet;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.Set;
+
+class LegacyPaperMeta {
+
+
+    private static final TypeToken<Map<PluginDependencyLifeCycle, Map<String, DependencyConfiguration>>> TYPE_TOKEN = new TypeToken<>() {
+    };
+
+    public static void migrate(CommentedConfigurationNode node) throws ConfigurateException {
+        ConfigurationTransformation.chain(notVersioned()).apply(node);
+    }
+
+    private static ConfigurationTransformation notVersioned() {
+        return ConfigurationTransformation.builder()
+            .addAction(NodePath.path(), (path, value) -> {
+                boolean bootstrapSubSection = value.hasChild("bootstrap");
+                boolean serverSubSection = value.hasChild("server");
+
+                // Ignore if using newer format
+                if (bootstrapSubSection || serverSubSection) {
+                    return null;
+                }
+
+                // First collect all load before elements
+                LegacyConfiguration legacyConfiguration;
+                try {
+                    legacyConfiguration = value.require(LegacyConfiguration.class);
+                } catch (SerializationException exception) {
+                    // Ignore if not present
+                    return null;
+                }
+
+                Map<PluginDependencyLifeCycle, Map<String, DependencyConfiguration>> dependencies = new EnumMap<>(PluginDependencyLifeCycle.class);
+                dependencies.put(PluginDependencyLifeCycle.BOOTSTRAP, new HashMap<>());
+                dependencies.put(PluginDependencyLifeCycle.SERVER, new HashMap<>());
+
+                Map<PluginDependencyLifeCycle, Map<String, Set<DependencyFlag>>> dependencyConfigurationMap = new HashMap<>();
+                dependencyConfigurationMap.put(PluginDependencyLifeCycle.BOOTSTRAP, new HashMap<>());
+                dependencyConfigurationMap.put(PluginDependencyLifeCycle.SERVER, new HashMap<>());
+
+                // Migrate loadafter
+                for (LegacyLoadConfiguration legacyConfig : legacyConfiguration.loadAfter) {
+                    Set<DependencyFlag> dependencyFlags = dependencyConfigurationMap
+                        .get(legacyConfig.bootstrap ? PluginDependencyLifeCycle.BOOTSTRAP : PluginDependencyLifeCycle.SERVER)
+                        .computeIfAbsent(legacyConfig.name, s -> EnumSet.noneOf(DependencyFlag.class));
+
+                    dependencyFlags.add(DependencyFlag.LOAD_AFTER);
+                }
+
+                // Migrate loadbefore
+                for (LegacyLoadConfiguration legacyConfig : legacyConfiguration.loadBefore) {
+                    Set<DependencyFlag> dependencyFlags = dependencyConfigurationMap
+                        .get(legacyConfig.bootstrap ? PluginDependencyLifeCycle.BOOTSTRAP : PluginDependencyLifeCycle.SERVER)
+                        .computeIfAbsent(legacyConfig.name, s -> EnumSet.noneOf(DependencyFlag.class));
+
+                    dependencyFlags.add(DependencyFlag.LOAD_BEFORE);
+                }
+
+                // Migrate dependencies
+                for (LegacyDependencyConfiguration legacyConfig : legacyConfiguration.dependencies) {
+                    Set<DependencyFlag> dependencyFlags = dependencyConfigurationMap
+                        .get(legacyConfig.bootstrap ? PluginDependencyLifeCycle.BOOTSTRAP : PluginDependencyLifeCycle.SERVER)
+                        .computeIfAbsent(legacyConfig.name, s -> EnumSet.noneOf(DependencyFlag.class));
+
+                    dependencyFlags.add(DependencyFlag.DEPENDENCY);
+                    if (legacyConfig.required) {
+                        dependencyFlags.add(DependencyFlag.REQUIRED);
+                    }
+                }
+                for (Map.Entry<PluginDependencyLifeCycle, Map<String, Set<DependencyFlag>>> legacyTypes : dependencyConfigurationMap.entrySet()) {
+                    Map<String, DependencyConfiguration> flagMap = dependencies.get(legacyTypes.getKey());
+                    for (Map.Entry<String, Set<DependencyFlag>> entry : legacyTypes.getValue().entrySet()) {
+                        Set<DependencyFlag> flags = entry.getValue();
+
+
+                        DependencyConfiguration.LoadOrder loadOrder = DependencyConfiguration.LoadOrder.OMIT;
+                        // These meanings are now swapped
+                        if (flags.contains(DependencyFlag.LOAD_BEFORE)) {
+                            loadOrder = DependencyConfiguration.LoadOrder.AFTER;
+                        } else if (flags.contains(DependencyFlag.LOAD_AFTER)) {
+                            loadOrder = DependencyConfiguration.LoadOrder.BEFORE;
+                        }
+
+                        flagMap.put(entry.getKey(), new DependencyConfiguration(
+                            loadOrder,
+                            flags.contains(DependencyFlag.REQUIRED),
+                            flags.contains(DependencyFlag.DEPENDENCY)
+                        ));
+                    }
+                }
+
+                value.node("dependencies").set(TYPE_TOKEN.getType(), dependencies);
+                return null;
+            })
+            .build();
+    }
+
+    @ConfigSerializable
+    record LegacyLoadConfiguration(
+        @Required String name,
+        boolean bootstrap
+    ) {
+    }
+
+    @ConfigSerializable
+    private static class LegacyConfiguration {
+
+        private List<LegacyLoadConfiguration> loadAfter = List.of();
+        private List<LegacyLoadConfiguration> loadBefore = List.of();
+        private List<LegacyDependencyConfiguration> dependencies = List.of();
+    }
+
+
+    @ConfigSerializable
+    public record LegacyDependencyConfiguration(
+        @Required String name,
+        boolean required,
+        boolean bootstrap
+    ) {
+    }
+
+    enum DependencyFlag {
+        LOAD_AFTER,
+        LOAD_BEFORE,
+        REQUIRED,
+        DEPENDENCY
+    }
+
+}

paper-server/src/main/java/io/papermc/paper/plugin/provider/configuration/LoadOrderConfiguration.java

@@ -0,0 +1,38 @@
+package io.papermc.paper.plugin.provider.configuration;
+
+import io.papermc.paper.plugin.configuration.PluginMeta;
+import org.jetbrains.annotations.NotNull;
+
+import java.util.List;
+
+/**
+ * This is used for plugins to configure the load order of strategies.
+ */
+public interface LoadOrderConfiguration {
+
+    /**
+     * Provides a list of plugins that THIS configuration should load
+     * before.
+     *
+     * @return list of plugins
+     */
+    @NotNull
+    List<String> getLoadBefore();
+
+    /**
+     * Provides a list of plugins that THIS configuration should load
+     * before.
+     *
+     * @return list of plugins
+     */
+    @NotNull
+    List<String> getLoadAfter();
+
+    /**
+     * Gets the responsible plugin provider's meta.
+     *
+     * @return meta
+     */
+    @NotNull
+    PluginMeta getMeta();
+}

paper-server/src/main/java/io/papermc/paper/plugin/provider/configuration/PaperPluginMeta.java

@@ -0,0 +1,271 @@
+package io.papermc.paper.plugin.provider.configuration;
+
+import com.google.common.base.Preconditions;
+import com.google.common.collect.ImmutableList;
+import io.papermc.paper.configuration.constraint.Constraint;
+import io.papermc.paper.configuration.serializer.ComponentSerializer;
+import io.papermc.paper.configuration.serializer.EnumValueSerializer;
+import io.papermc.paper.plugin.configuration.PluginMeta;
+import io.papermc.paper.plugin.provider.configuration.serializer.PermissionConfigurationSerializer;
+import io.papermc.paper.plugin.provider.configuration.serializer.constraints.PluginConfigConstraints;
+import io.papermc.paper.plugin.provider.configuration.type.DependencyConfiguration;
+import io.papermc.paper.plugin.provider.configuration.type.PermissionConfiguration;
+import io.papermc.paper.plugin.provider.configuration.type.PluginDependencyLifeCycle;
+import java.lang.reflect.Type;
+import java.util.function.Predicate;
+import org.bukkit.craftbukkit.util.ApiVersion;
+import org.bukkit.permissions.Permission;
+import org.bukkit.permissions.PermissionDefault;
+import org.bukkit.plugin.PluginLoadOrder;
+import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
+import org.jetbrains.annotations.TestOnly;
+import org.spongepowered.configurate.CommentedConfigurationNode;
+import org.spongepowered.configurate.ConfigurateException;
+import org.spongepowered.configurate.loader.HeaderMode;
+import org.spongepowered.configurate.objectmapping.ConfigSerializable;
+import org.spongepowered.configurate.objectmapping.ObjectMapper;
+import org.spongepowered.configurate.objectmapping.meta.Required;
+import org.spongepowered.configurate.serialize.ScalarSerializer;
+import org.spongepowered.configurate.serialize.SerializationException;
+import org.spongepowered.configurate.yaml.NodeStyle;
+import org.spongepowered.configurate.yaml.YamlConfigurationLoader;
+
+import java.io.BufferedReader;
+import java.util.EnumMap;
+import java.util.List;
+import java.util.Map;
+
+@SuppressWarnings({"CanBeFinal", "FieldCanBeLocal", "FieldMayBeFinal", "NotNullFieldNotInitialized", "InnerClassMayBeStatic"})
+@ConfigSerializable
+public class PaperPluginMeta implements PluginMeta {
+
+    @PluginConfigConstraints.PluginName
+    @Required
+    private String name;
+    @Required
+    @PluginConfigConstraints.PluginNameSpace
+    private String main;
+    @PluginConfigConstraints.PluginNameSpace
+    private String bootstrapper;
+    @PluginConfigConstraints.PluginNameSpace
+    private String loader;
+    private List<String> provides = List.of();
+    private boolean hasOpenClassloader = false;
+    @Required
+    private String version;
+    private String description;
+    private List<String> authors = List.of();
+    private List<String> contributors = List.of();
+    private String website;
+    private String prefix;
+    private PluginLoadOrder load = PluginLoadOrder.POSTWORLD;
+    @FlattenedResolver
+    private PermissionConfiguration permissionConfiguration = new PermissionConfiguration(PermissionDefault.OP, List.of());
+    @Required
+    private ApiVersion apiVersion;
+
+    private Map<PluginDependencyLifeCycle, Map<String, DependencyConfiguration>> dependencies = new EnumMap<>(PluginDependencyLifeCycle.class);
+
+    public PaperPluginMeta() {
+    }
+
+    static final ApiVersion MINIMUM = ApiVersion.getOrCreateVersion("1.19");
+    public static PaperPluginMeta create(BufferedReader reader) throws ConfigurateException {
+        YamlConfigurationLoader loader = YamlConfigurationLoader.builder()
+            .indent(2)
+            .nodeStyle(NodeStyle.BLOCK)
+            .headerMode(HeaderMode.NONE)
+            .source(() -> reader)
+            .defaultOptions((options) -> {
+
+                return options.serializers((serializers) -> {
+                    serializers
+                        .register(new ScalarSerializer<>(ApiVersion.class) {
+                            @Override
+                            public ApiVersion deserialize(final Type type, final Object obj) throws SerializationException {
+                                try {
+                                    final ApiVersion version = ApiVersion.getOrCreateVersion(obj.toString());
+                                    if (version.isOlderThan(MINIMUM)) {
+                                        throw new SerializationException(version + " is too old for a paper plugin!");
+                                    }
+                                    return version;
+                                } catch (final IllegalArgumentException e) {
+                                    throw new SerializationException(e);
+                                }
+                            }
+
+                            @Override
+                            protected Object serialize(final ApiVersion item, final Predicate<Class<?>> typeSupported) {
+                                return item.getVersionString();
+                            }
+                        })
+                        .register(new EnumValueSerializer())
+                        .register(PermissionConfiguration.class, PermissionConfigurationSerializer.SERIALIZER)
+                        .register(new ComponentSerializer())
+                        .registerAnnotatedObjects(
+                            ObjectMapper.factoryBuilder()
+                                .addConstraint(Constraint.class, new Constraint.Factory())
+                                .addConstraint(PluginConfigConstraints.PluginName.class, String.class, new PluginConfigConstraints.PluginName.Factory())
+                                .addConstraint(PluginConfigConstraints.PluginNameSpace.class, String.class, new PluginConfigConstraints.PluginNameSpace.Factory())
+                                .addNodeResolver(new FlattenedResolver.Factory())
+                                .build()
+                        );
+
+                });
+            })
+            .build();
+        CommentedConfigurationNode node = loader.load();
+        LegacyPaperMeta.migrate(node);
+        PaperPluginMeta pluginConfiguration = node.require(PaperPluginMeta.class);
+
+        if (!node.node("author").virtual()) {
+            pluginConfiguration.authors = ImmutableList.<String>builder()
+                .addAll(pluginConfiguration.authors)
+                .add(node.node("author").getString())
+                .build();
+        }
+
+        return pluginConfiguration;
+    }
+
+    @Override
+    public @NotNull String getName() {
+        return this.name;
+    }
+
+    @TestOnly
+    public void setName(@NotNull String name) {
+        Preconditions.checkNotNull(name, "name");
+        this.name = name;
+    }
+
+    @Override
+    public @NotNull String getMainClass() {
+        return this.main;
+    }
+
+    @Override
+    public @NotNull String getVersion() {
+        return this.version;
+    }
+
+    @TestOnly
+    public void setVersion(@NotNull String version) {
+        Preconditions.checkNotNull(version, "version");
+        this.version = version;
+    }
+
+    @Override
+    public @Nullable String getLoggerPrefix() {
+        return this.prefix;
+    }
+
+    @Override
+    public @NotNull List<String> getPluginDependencies() {
+        return this.dependencies.getOrDefault(PluginDependencyLifeCycle.SERVER, Map.of())
+            .entrySet()
+            .stream()
+            .filter((entry) -> entry.getValue().required() && entry.getValue().joinClasspath())
+            .map(Map.Entry::getKey)
+            .toList();
+    }
+
+    @Override
+    public @NotNull List<String> getPluginSoftDependencies() {
+        return this.dependencies.getOrDefault(PluginDependencyLifeCycle.SERVER, Map.of())
+            .entrySet()
+            .stream()
+            .filter((entry) -> !entry.getValue().required() && entry.getValue().joinClasspath())
+            .map(Map.Entry::getKey)
+            .toList();
+    }
+
+    @Override
+    public @NotNull List<String> getLoadBeforePlugins() {
+        return this.dependencies.getOrDefault(PluginDependencyLifeCycle.SERVER, Map.of())
+            .entrySet()
+            .stream()
+            // This plugin will load BEFORE all dependencies (so dependencies will load AFTER plugin)
+            .filter((entry) -> entry.getValue().load() == DependencyConfiguration.LoadOrder.AFTER)
+            .map(Map.Entry::getKey)
+            .toList();
+    }
+
+    public @NotNull List<String> getLoadAfterPlugins() {
+        return this.dependencies.getOrDefault(PluginDependencyLifeCycle.SERVER, Map.of())
+            .entrySet()
+            .stream()
+            // This plugin will load AFTER all dependencies (so dependencies will load BEFORE plugin)
+            .filter((entry) -> entry.getValue().load() == DependencyConfiguration.LoadOrder.BEFORE)
+            .map(Map.Entry::getKey)
+            .toList();
+    }
+
+
+    public Map<String, DependencyConfiguration> getServerDependencies() {
+        return this.dependencies.getOrDefault(PluginDependencyLifeCycle.SERVER, Map.of());
+    }
+
+    public Map<String, DependencyConfiguration> getBootstrapDependencies() {
+        return this.dependencies.getOrDefault(PluginDependencyLifeCycle.BOOTSTRAP, Map.of());
+    }
+
+    @Override
+    public @NotNull PluginLoadOrder getLoadOrder() {
+        return this.load;
+    }
+
+    @Override
+    public @NotNull String getDescription() {
+        return this.description;
+    }
+
+    @Override
+    public @NotNull List<String> getAuthors() {
+        return this.authors;
+    }
+
+    @Override
+    public @NotNull List<String> getContributors() {
+        return this.contributors;
+    }
+
+    @Override
+    public String getWebsite() {
+        return this.website;
+    }
+
+    @Override
+    public @NotNull List<Permission> getPermissions() {
+        return this.permissionConfiguration.permissions();
+    }
+
+    @Override
+    public @NotNull PermissionDefault getPermissionDefault() {
+        return this.permissionConfiguration.defaultPerm();
+    }
+
+    @Override
+    public @NotNull String getAPIVersion() {
+        return this.apiVersion.getVersionString();
+    }
+
+    @Override
+    public @NotNull List<String> getProvidedPlugins() {
+        return this.provides;
+    }
+
+    public String getBootstrapper() {
+        return this.bootstrapper;
+    }
+
+    public String getLoader() {
+        return this.loader;
+    }
+
+    public boolean hasOpenClassloader() {
+        return this.hasOpenClassloader;
+    }
+
+}

paper-server/src/main/java/io/papermc/paper/plugin/provider/configuration/serializer/ImmutableCollectionSerializer.java

@@ -0,0 +1,90 @@
+package io.papermc.paper.plugin.provider.configuration.serializer;
+
+import com.google.common.collect.ImmutableCollection;
+import org.checkerframework.checker.nullness.qual.Nullable;
+import org.spongepowered.configurate.ConfigurationNode;
+import org.spongepowered.configurate.ConfigurationOptions;
+import org.spongepowered.configurate.serialize.SerializationException;
+import org.spongepowered.configurate.serialize.TypeSerializer;
+import org.spongepowered.configurate.util.CheckedConsumer;
+
+import java.lang.reflect.Type;
+import java.util.Collection;
+import java.util.Collections;
+import java.util.List;
+
+@SuppressWarnings("unchecked")
+public abstract class ImmutableCollectionSerializer<B extends ImmutableCollection.Builder<?>, T extends Collection<?>> implements TypeSerializer<T> {
+
+    protected ImmutableCollectionSerializer() {
+    }
+
+    @Override
+    public final T deserialize(final Type type, final ConfigurationNode node) throws SerializationException {
+        final Type entryType = this.elementType(type);
+        final @Nullable TypeSerializer<?> entrySerial = node.options().serializers().get(entryType);
+        if (entrySerial == null) {
+            throw new SerializationException(node, entryType, "No applicable type serializer for type");
+        }
+
+        if (node.isList()) {
+            final List<? extends ConfigurationNode> values = node.childrenList();
+            final B builder = this.createNew(values.size());
+            for (ConfigurationNode value : values) {
+                try {
+                    this.deserializeSingle(builder, entrySerial.deserialize(entryType, value));
+                } catch (final SerializationException ex) {
+                    ex.initPath(value::path);
+                    throw ex;
+                }
+            }
+            return (T) builder.build();
+        } else {
+            final @Nullable Object unwrappedVal = node.raw();
+            if (unwrappedVal != null) {
+                final B builder = this.createNew(1);
+                this.deserializeSingle(builder, entrySerial.deserialize(entryType, node));
+                return (T) builder.build();
+            }
+        }
+        return this.emptyValue(type, null);
+    }
+
+    @SuppressWarnings({"unchecked", "rawtypes"})
+    @Override
+    public final void serialize(final Type type, final @Nullable T obj, final ConfigurationNode node) throws SerializationException {
+        final Type entryType = this.elementType(type);
+        final @Nullable TypeSerializer entrySerial = node.options().serializers().get(entryType);
+        if (entrySerial == null) {
+            throw new SerializationException(node, entryType, "No applicable type serializer for type");
+        }
+
+        node.raw(Collections.emptyList());
+        if (obj != null) {
+            this.forEachElement(obj, el -> {
+                final ConfigurationNode child = node.appendListNode();
+                try {
+                    entrySerial.serialize(entryType, el, child);
+                } catch (final SerializationException ex) {
+                    ex.initPath(child::path);
+                    throw ex;
+                }
+            });
+        }
+    }
+
+    @SuppressWarnings({"unchecked"})
+    @Override
+    public @Nullable T emptyValue(final Type specificType, final ConfigurationOptions options) {
+        return (T) this.createNew(0).build();
+    }
+
+    protected abstract Type elementType(Type containerType) throws SerializationException;
+
+    protected abstract B createNew(int size);
+
+    protected abstract void forEachElement(T collection, CheckedConsumer<Object, SerializationException> action) throws SerializationException;
+
+    protected abstract void deserializeSingle(B builder, @Nullable Object deserialized) throws SerializationException;
+
+}

paper-server/src/main/java/io/papermc/paper/plugin/provider/configuration/serializer/ImmutableListSerializer.java

@@ -0,0 +1,43 @@
+package io.papermc.paper.plugin.provider.configuration.serializer;
+
+import com.google.common.collect.ImmutableList;
+import org.checkerframework.checker.nullness.qual.Nullable;
+import org.spongepowered.configurate.serialize.SerializationException;
+import org.spongepowered.configurate.util.CheckedConsumer;
+
+import java.lang.reflect.ParameterizedType;
+import java.lang.reflect.Type;
+import java.util.List;
+
+public class ImmutableListSerializer extends ImmutableCollectionSerializer<ImmutableList.Builder<?>, List<?>> {
+
+    @Override
+    protected Type elementType(Type containerType) throws SerializationException {
+        if (!(containerType instanceof ParameterizedType)) {
+            throw new SerializationException(containerType, "Raw types are not supported for collections");
+        }
+        return ((ParameterizedType) containerType).getActualTypeArguments()[0];
+    }
+
+    @Override
+    protected ImmutableList.Builder<?> createNew(int size) {
+        return ImmutableList.builderWithExpectedSize(size);
+    }
+
+    @Override
+    protected void forEachElement(List<?> collection, CheckedConsumer<Object, SerializationException> action) throws SerializationException {
+        for (Object obj : collection) {
+            action.accept(obj);
+        }
+    }
+
+    @SuppressWarnings({"unchecked", "rawtypes"})
+    @Override
+    protected void deserializeSingle(ImmutableList.Builder<?> builder, @Nullable Object deserialized) throws SerializationException {
+        if (deserialized == null) {
+            return;
+        }
+
+        ((ImmutableList.Builder) builder).add(deserialized);
+    }
+}

paper-server/src/main/java/io/papermc/paper/plugin/provider/configuration/serializer/PermissionConfigurationSerializer.java

@@ -0,0 +1,56 @@
+package io.papermc.paper.plugin.provider.configuration.serializer;
+
+import io.papermc.paper.plugin.provider.configuration.type.PermissionConfiguration;
+import org.bukkit.permissions.Permission;
+import org.bukkit.permissions.PermissionDefault;
+import org.spongepowered.configurate.ConfigurationNode;
+import org.spongepowered.configurate.serialize.SerializationException;
+import org.spongepowered.configurate.serialize.TypeSerializer;
+
+import java.lang.reflect.Type;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Map;
+
+public class PermissionConfigurationSerializer {
+
+    public static final Serializer SERIALIZER = new Serializer();
+
+    private static final class Serializer implements TypeSerializer<PermissionConfiguration> {
+        private Serializer() {
+            super();
+        }
+
+        @Override
+        public PermissionConfiguration deserialize(Type type, ConfigurationNode node) throws SerializationException {
+            Map<?, ?> map = (Map<?, ?>) node.node("permissions").raw();
+
+            PermissionDefault permissionDefault;
+            ConfigurationNode permNode = node.node("defaultPerm");
+            if (permNode.virtual()) {
+                permissionDefault = PermissionDefault.OP;
+            } else {
+                permissionDefault = PermissionDefault.getByName(permNode.getString());
+            }
+
+            List<Permission> result = new ArrayList<>();
+            if (map != null) {
+                for (Map.Entry<?, ?> entry : map.entrySet()) {
+                    try {
+                        result.add(Permission.loadPermission(entry.getKey().toString(), (Map<?, ?>) entry.getValue(), permissionDefault, result));
+                    } catch (Throwable ex) {
+                        throw new SerializationException((Type) null, "Error loading permission %s".formatted(entry.getKey()), ex);
+                    }
+                }
+            }
+
+            return new PermissionConfiguration(permissionDefault, List.copyOf(result));
+        }
+
+        @Override
+        public void serialize(Type type, @org.checkerframework.checker.nullness.qual.Nullable PermissionConfiguration obj, ConfigurationNode node) throws SerializationException {
+
+        }
+
+    }
+}

paper-server/src/main/java/io/papermc/paper/plugin/provider/configuration/serializer/constraints/PluginConfigConstraints.java

@@ -0,0 +1,67 @@
+package io.papermc.paper.plugin.provider.configuration.serializer.constraints;
+
+import io.papermc.paper.plugin.util.NamespaceChecker;
+import org.spongepowered.configurate.objectmapping.meta.Constraint;
+import org.spongepowered.configurate.serialize.SerializationException;
+
+import java.lang.annotation.Documented;
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+import java.lang.reflect.Type;
+import java.util.Locale;
+import java.util.Set;
+import java.util.regex.Pattern;
+
+public final class PluginConfigConstraints {
+
+    public static final Set<String> RESERVED_KEYS = Set.of("bukkit", "minecraft", "mojang", "spigot", "paper");
+
+    @Documented
+    @Retention(RetentionPolicy.RUNTIME)
+    @Target(ElementType.FIELD)
+    public @interface PluginName {
+
+        final class Factory implements Constraint.Factory<PluginName, String> {
+
+            private static final Pattern VALID_NAME = Pattern.compile("^[A-Za-z\\d _.-]+$");
+
+            @Override
+            public Constraint<String> make(PluginName data, Type type) {
+                return value -> {
+                    if (value != null) {
+                        if (RESERVED_KEYS.contains(value.toLowerCase(Locale.ROOT))) {
+                            throw new SerializationException("Restricted name, cannot use '%s' as a plugin name.".formatted(data));
+                        } else if (value.indexOf(' ') != -1) {
+                            // For legacy reasons, the space condition has a separate exception message.
+                            throw new SerializationException("Restricted name, cannot use 0x20 (space character) in a plugin name.");
+                        }
+
+                        if (!VALID_NAME.matcher(value).matches()) {
+                            throw new SerializationException("name '" + value + "' contains invalid characters.");
+                        }
+                    }
+                };
+            }
+        }
+    }
+
+    @Documented
+    @Retention(RetentionPolicy.RUNTIME)
+    @Target(ElementType.FIELD)
+    public @interface PluginNameSpace {
+
+        final class Factory implements Constraint.Factory<PluginNameSpace, String> {
+
+            @Override
+            public Constraint<String> make(PluginNameSpace data, Type type) {
+                return value -> {
+                    if (value != null && !NamespaceChecker.isValidNameSpace(value)) {
+                        throw new SerializationException("provided class '%s' is in an invalid namespace.".formatted(value));
+                    }
+                };
+            }
+        }
+    }
+}

paper-server/src/main/java/io/papermc/paper/plugin/provider/configuration/type/DependencyConfiguration.java

@@ -0,0 +1,30 @@
+package io.papermc.paper.plugin.provider.configuration.type;
+
+import org.checkerframework.checker.nullness.qual.NonNull;
+import org.checkerframework.framework.qual.DefaultQualifier;
+import org.spongepowered.configurate.objectmapping.ConfigSerializable;
+
+import static java.util.Objects.requireNonNullElse;
+
+@DefaultQualifier(NonNull.class)
+@ConfigSerializable
+public record DependencyConfiguration(
+    LoadOrder load,
+    Boolean required,
+    Boolean joinClasspath
+) {
+    @SuppressWarnings("DataFlowIssue") // incorrect intellij inspections
+    public DependencyConfiguration {
+        required = requireNonNullElse(required, true);
+        joinClasspath = requireNonNullElse(joinClasspath, true);
+    }
+
+    @ConfigSerializable
+    public enum LoadOrder {
+        // dependency will now load BEFORE your plugin
+        BEFORE,
+        // the dependency will now load AFTER your plugin
+        AFTER,
+        OMIT
+    }
+}

paper-server/src/main/java/io/papermc/paper/plugin/provider/configuration/type/LoadConfiguration.java

@@ -0,0 +1,11 @@
+package io.papermc.paper.plugin.provider.configuration.type;
+
+import org.spongepowered.configurate.objectmapping.ConfigSerializable;
+import org.spongepowered.configurate.objectmapping.meta.Required;
+
+@ConfigSerializable
+public record LoadConfiguration(
+    @Required String name,
+    boolean bootstrap
+) {
+}

paper-server/src/main/java/io/papermc/paper/plugin/provider/configuration/type/PermissionConfiguration.java

@@ -0,0 +1,14 @@
+package io.papermc.paper.plugin.provider.configuration.type;
+
+import org.bukkit.permissions.Permission;
+import org.bukkit.permissions.PermissionDefault;
+import org.spongepowered.configurate.objectmapping.ConfigSerializable;
+
+import java.util.List;
+
+// Record components used for deserialization!!!!
+@ConfigSerializable
+public record PermissionConfiguration(
+    PermissionDefault defaultPerm,
+    List<Permission> permissions) {
+}

paper-server/src/main/java/io/papermc/paper/plugin/provider/configuration/type/PluginDependencyLifeCycle.java

@@ -0,0 +1,6 @@
+package io.papermc.paper.plugin.provider.configuration.type;
+
+public enum PluginDependencyLifeCycle {
+    BOOTSTRAP,
+    SERVER
+}

paper-server/src/main/java/io/papermc/paper/plugin/provider/source/DirectoryProviderSource.java

@@ -0,0 +1,66 @@
+package io.papermc.paper.plugin.provider.source;
+
+import com.mojang.logging.LogUtils;
+import io.papermc.paper.plugin.entrypoint.EntrypointHandler;
+import java.io.IOException;
+import java.nio.file.FileVisitOption;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.function.Consumer;
+import org.slf4j.Logger;
+
+/**
+ * Loads all plugin providers in the given directory.
+ */
+public class DirectoryProviderSource implements ProviderSource<Path, List<Path>> {
+
+    public static final DirectoryProviderSource INSTANCE = new DirectoryProviderSource();
+    private static final FileProviderSource FILE_PROVIDER_SOURCE = new FileProviderSource("Directory '%s'"::formatted);
+    private static final Logger LOGGER = LogUtils.getClassLogger();
+
+    @Override
+    public List<Path> prepareContext(Path context) throws IOException {
+        // Symlink happy, create file if missing.
+        if (!Files.isDirectory(context)) {
+            Files.createDirectories(context);
+        }
+
+        final List<Path> files = new ArrayList<>();
+        this.walkFiles(context, path -> {
+            try {
+                files.add(FILE_PROVIDER_SOURCE.prepareContext(path));
+            } catch (IllegalArgumentException ignored) {
+                // Ignore illegal argument exceptions from jar checking
+            } catch (final Exception e) {
+                LOGGER.error("Error preparing plugin context: " + e.getMessage(), e);
+            }
+        });
+        return files;
+    }
+
+    @Override
+    public void registerProviders(EntrypointHandler entrypointHandler, List<Path> context) {
+        for (Path path : context) {
+            try {
+                FILE_PROVIDER_SOURCE.registerProviders(entrypointHandler, path);
+            } catch (IllegalArgumentException ignored) {
+                // Ignore illegal argument exceptions from jar checking
+            } catch (Exception e) {
+                LOGGER.error("Error loading plugin: " + e.getMessage(), e);
+            }
+        }
+    }
+
+    private void walkFiles(Path context, Consumer<Path> consumer) throws IOException {
+        Files.walk(context, 1, FileVisitOption.FOLLOW_LINKS)
+            .filter(this::isValidFile)
+            .forEach(consumer);
+    }
+
+    public boolean isValidFile(Path path) {
+        // Avoid loading plugins that start with a dot
+        return Files.isRegularFile(path) && !path.startsWith(".");
+    }
+}

paper-server/src/main/java/io/papermc/paper/plugin/provider/source/FileArrayProviderSource.java

@@ -0,0 +1,44 @@
+package io.papermc.paper.plugin.provider.source;
+
+import com.mojang.logging.LogUtils;
+import io.papermc.paper.plugin.entrypoint.EntrypointHandler;
+import java.io.File;
+import java.nio.file.Path;
+import java.util.ArrayList;
+import java.util.List;
+import org.slf4j.Logger;
+
+public class FileArrayProviderSource implements ProviderSource<File[], List<Path>> {
+
+    public static final FileArrayProviderSource INSTANCE = new FileArrayProviderSource();
+    private static final FileProviderSource FILE_PROVIDER_SOURCE = new FileProviderSource("File '%s'"::formatted);
+    private static final Logger LOGGER = LogUtils.getClassLogger();
+
+    @Override
+    public List<Path> prepareContext(File[] context) {
+        final List<Path> files = new ArrayList<>();
+        for (File file : context) {
+            try {
+                files.add(FILE_PROVIDER_SOURCE.prepareContext(file.toPath()));
+            } catch (IllegalArgumentException ignored) {
+                // Ignore illegal argument exceptions from jar checking
+            } catch (final Exception e) {
+                LOGGER.error("Error preparing plugin context: " + e.getMessage(), e);
+            }
+        }
+        return files;
+    }
+
+    @Override
+    public void registerProviders(EntrypointHandler entrypointHandler, List<Path> context) {
+        for (Path path : context) {
+            try {
+                FILE_PROVIDER_SOURCE.registerProviders(entrypointHandler, path);
+            } catch (IllegalArgumentException ignored) {
+                // Ignore illegal argument exceptions from jar checking
+            } catch (Exception e) {
+                LOGGER.error("Error loading plugin: " + e.getMessage(), e);
+            }
+        }
+    }
+}

paper-server/src/main/java/io/papermc/paper/plugin/provider/source/FileProviderSource.java

@@ -0,0 +1,171 @@
+package io.papermc.paper.plugin.provider.source;
+
+import io.papermc.paper.plugin.PluginInitializerManager;
+import io.papermc.paper.plugin.entrypoint.EntrypointHandler;
+import io.papermc.paper.plugin.provider.type.PluginFileType;
+import org.bukkit.plugin.InvalidPluginException;
+import org.jetbrains.annotations.Nullable;
+
+import java.io.File;
+import java.io.IOException;
+import java.nio.file.FileVisitResult;
+import java.nio.file.FileVisitor;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.nio.file.StandardCopyOption;
+import java.nio.file.attribute.BasicFileAttributes;
+import java.util.Set;
+import java.util.function.Function;
+import java.util.jar.JarFile;
+
+/**
+ * Loads a plugin provider at the given plugin jar file path.
+ */
+public class FileProviderSource implements ProviderSource<Path, Path> {
+
+    private final Function<Path, String> contextChecker;
+
+    public FileProviderSource(Function<Path, String> contextChecker) {
+        this.contextChecker = contextChecker;
+    }
+
+    @Override
+    public Path prepareContext(Path context) throws IOException {
+        String source = this.contextChecker.apply(context);
+
+        if (Files.notExists(context)) {
+            throw new IllegalArgumentException(source + " does not exist, cannot load a plugin from it!");
+        }
+
+        if (!Files.isRegularFile(context)) {
+            throw new IllegalArgumentException(source + " is not a file, cannot load a plugin from it!");
+        }
+
+        if (!context.getFileName().toString().endsWith(".jar")) {
+            throw new IllegalArgumentException(source + " is not a jar file, cannot load a plugin from it!");
+        }
+
+        try {
+            context = this.checkUpdate(context);
+        } catch (Exception exception) {
+            throw new RuntimeException(source + " failed to update!", exception);
+        }
+        return context;
+    }
+
+    @Override
+    public void registerProviders(EntrypointHandler entrypointHandler, Path context) throws Exception {
+        String source = this.contextChecker.apply(context);
+
+        JarFile file = new JarFile(context.toFile(), true, JarFile.OPEN_READ, JarFile.runtimeVersion());
+        PluginFileType<?, ?> type = PluginFileType.guessType(file);
+        if (type == null) {
+            // Throw IAE wrapped in RE to prevent callers from considering this a "invalid parameter" as caller ignores IAE.
+            // TODO: This needs some heavy rework, using illegal argument exception to signal an actual failure is less than ideal.
+            if (file.getEntry("META-INF/versions.list") != null) {
+                throw new RuntimeException(new IllegalArgumentException(context + " appears to be a server jar! Server jars do not belong in the plugin folder."));
+            }
+
+            throw new RuntimeException(
+                new IllegalArgumentException(source + " does not contain a " + String.join(" or ", PluginFileType.getConfigTypes()) + "! Could not determine plugin type, cannot load a plugin from it!")
+            );
+        }
+
+        type.register(entrypointHandler, file, context);
+    }
+
+    /**
+     * Replaces a plugin with a plugin of the same plugin name in the update folder.
+     *
+     * @param file
+     */
+    private Path checkUpdate(Path file) throws InvalidPluginException {
+        PluginInitializerManager pluginSystem = PluginInitializerManager.instance();
+        Path updateDirectory = pluginSystem.pluginUpdatePath();
+        if (updateDirectory == null || !Files.isDirectory(updateDirectory)) {
+            return file;
+        }
+
+        try {
+            String pluginName = this.getPluginName(file);
+            UpdateFileVisitor visitor = new UpdateFileVisitor(pluginName);
+            Files.walkFileTree(updateDirectory, Set.of(), 1, visitor);
+            if (visitor.getValidPlugin() != null) {
+                Path updateLocation = visitor.getValidPlugin();
+
+                try {
+                    Files.copy(updateLocation, file, StandardCopyOption.REPLACE_EXISTING);
+                } catch (IOException exception) {
+                    throw new RuntimeException("Could not copy '" + updateLocation + "' to '" + file + "' in update plugin process", exception);
+                }
+
+                // Idk what this is about, TODO
+                File newName = new File(file.toFile().getParentFile(), updateLocation.toFile().getName());
+                file.toFile().renameTo(newName);
+                updateLocation.toFile().delete();
+                return newName.toPath();
+            }
+        } catch (Exception e) {
+            throw new InvalidPluginException(e);
+        }
+        return file;
+    }
+
+    private String getPluginName(Path path) throws Exception {
+        try (JarFile file = new JarFile(path.toFile())) {
+            PluginFileType<?, ?> type = PluginFileType.guessType(file);
+            if (type == null) {
+                throw new IllegalArgumentException(path + " does not contain a " + String.join(" or ", PluginFileType.getConfigTypes()) + "! Could not determine plugin type, cannot load a plugin from it!");
+            }
+
+            return type.getConfig(file).getName();
+        }
+    }
+
+    private class UpdateFileVisitor implements FileVisitor<Path> {
+
+        private final String targetName;
+        @Nullable
+        private Path validPlugin;
+
+        private UpdateFileVisitor(String targetName) {
+            this.targetName = targetName;
+        }
+
+        @Override
+        public FileVisitResult preVisitDirectory(Path dir, BasicFileAttributes attrs) throws IOException {
+            return FileVisitResult.CONTINUE;
+        }
+
+        @Override
+        public FileVisitResult visitFile(Path file, BasicFileAttributes attrs) throws IOException {
+            try {
+                String updatePluginName = FileProviderSource.this.getPluginName(file);
+                if (this.targetName.equals(updatePluginName)) {
+                    this.validPlugin = file;
+                    return FileVisitResult.TERMINATE;
+                }
+            } catch (Exception e) {
+                // We failed to load this data for some reason, so, we'll skip over this
+            }
+
+
+            return FileVisitResult.CONTINUE;
+        }
+
+        @Override
+        public FileVisitResult visitFileFailed(Path file, IOException exc) throws IOException {
+            return FileVisitResult.CONTINUE;
+        }
+
+        @Override
+        public FileVisitResult postVisitDirectory(Path dir, IOException exc) throws IOException {
+            return FileVisitResult.CONTINUE;
+        }
+
+        @Nullable
+        public Path getValidPlugin() {
+            return validPlugin;
+        }
+    }
+}

paper-server/src/main/java/io/papermc/paper/plugin/provider/source/PluginFlagProviderSource.java

@@ -0,0 +1,43 @@
+package io.papermc.paper.plugin.provider.source;
+
+import com.mojang.logging.LogUtils;
+import io.papermc.paper.plugin.entrypoint.EntrypointHandler;
+import java.nio.file.Path;
+import java.util.ArrayList;
+import org.slf4j.Logger;
+
+import java.util.List;
+
+/**
+ * Registers providers at the provided files in the add-plugin argument.
+ */
+public class PluginFlagProviderSource implements ProviderSource<List<Path>, List<Path>> {
+
+    public static final PluginFlagProviderSource INSTANCE = new PluginFlagProviderSource();
+    private static final FileProviderSource FILE_PROVIDER_SOURCE = new FileProviderSource("File '%s' specified through 'add-plugin' argument"::formatted);
+    private static final Logger LOGGER = LogUtils.getClassLogger();
+
+    @Override
+    public List<Path> prepareContext(List<Path> context) {
+        final List<Path> files = new ArrayList<>();
+        for (Path path : context) {
+            try {
+                files.add(FILE_PROVIDER_SOURCE.prepareContext(path));
+            } catch (Exception e) {
+                LOGGER.error("Error preparing plugin context: " + e.getMessage(), e);
+            }
+        }
+        return files;
+    }
+
+    @Override
+    public void registerProviders(EntrypointHandler entrypointHandler, List<Path> context) {
+        for (Path path : context) {
+            try {
+                FILE_PROVIDER_SOURCE.registerProviders(entrypointHandler, path);
+            } catch (Exception e) {
+                LOGGER.error("Error loading plugin: " + e.getMessage(), e);
+            }
+        }
+    }
+}

paper-server/src/main/java/io/papermc/paper/plugin/provider/source/ProviderSource.java

@@ -0,0 +1,32 @@
+package io.papermc.paper.plugin.provider.source;
+
+import io.papermc.paper.plugin.entrypoint.EntrypointHandler;
+import java.io.IOException;
+
+/**
+ * A provider source is responsible for giving PluginTypes an EntrypointHandler for
+ * registering providers at.
+ *
+ * @param <I> input context
+ * @param <C> context
+ */
+public interface ProviderSource<I, C> {
+
+    /**
+     * Prepares the context for use in {@link #registerProviders(EntrypointHandler, Object)}.
+     *
+     * @param context the context to prepare
+     * @return the prepared context, ready for use in {@link #registerProviders(EntrypointHandler, Object)}
+     * @throws IOException if an error occurs while preparing the context
+     */
+    C prepareContext(I context) throws IOException;
+
+    /**
+     * Uses the prepared context to register providers at the given entrypoint handler.
+     *
+     * @param entrypointHandler the entrypoint handler to register providers at
+     * @param context           the context to register providers at
+     * @throws Exception if an error occurs while registering providers
+     */
+    void registerProviders(EntrypointHandler entrypointHandler, C context) throws Exception;
+}

paper-server/src/main/java/io/papermc/paper/plugin/provider/type/PluginFileType.java

@@ -0,0 +1,85 @@
+package io.papermc.paper.plugin.provider.type;
+
+import io.papermc.paper.plugin.configuration.PluginMeta;
+import io.papermc.paper.plugin.entrypoint.Entrypoint;
+import io.papermc.paper.plugin.entrypoint.EntrypointHandler;
+import io.papermc.paper.plugin.provider.configuration.PaperPluginMeta;
+import io.papermc.paper.plugin.provider.type.paper.PaperPluginParent;
+import io.papermc.paper.plugin.provider.type.spigot.SpigotPluginProvider;
+import org.bukkit.plugin.PluginDescriptionFile;
+import org.jetbrains.annotations.Nullable;
+
+import java.nio.file.Path;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.jar.JarEntry;
+import java.util.jar.JarFile;
+
+/**
+ * This is where spigot/paper plugins are registered.
+ * This will get the jar and find a certain config file, create an object
+ * then registering it into a {@link EntrypointHandler} at a certain {@link Entrypoint}.
+ */
+public abstract class PluginFileType<T, C extends PluginMeta> {
+
+    private static final List<String> CONFIG_TYPES = new ArrayList<>();
+    
+    public static final PluginFileType<PaperPluginParent, PaperPluginMeta> PAPER = new PluginFileType<>("paper-plugin.yml", PaperPluginParent.FACTORY) {
+        @Override
+        protected void register(EntrypointHandler entrypointHandler, PaperPluginParent parent) {
+            PaperPluginParent.PaperBootstrapProvider bootstrapPluginProvider = null;
+            if (parent.shouldCreateBootstrap()) {
+                bootstrapPluginProvider = parent.createBootstrapProvider();
+                entrypointHandler.register(Entrypoint.BOOTSTRAPPER, bootstrapPluginProvider);
+            }
+
+            entrypointHandler.register(Entrypoint.PLUGIN, parent.createPluginProvider(bootstrapPluginProvider));
+        }
+    };
+    public static final PluginFileType<SpigotPluginProvider, PluginDescriptionFile> SPIGOT = new PluginFileType<>("plugin.yml", SpigotPluginProvider.FACTORY) {
+        @Override
+        protected void register(EntrypointHandler entrypointHandler, SpigotPluginProvider provider) {
+            entrypointHandler.register(Entrypoint.PLUGIN, provider);
+        }
+    };
+
+    private static final List<PluginFileType<?, ?>> VALUES = List.of(PAPER, SPIGOT);
+
+    private final String config;
+    private final PluginTypeFactory<T, C> factory;
+
+    PluginFileType(String config, PluginTypeFactory<T, C> factory) {
+        this.config = config;
+        this.factory = factory;
+        CONFIG_TYPES.add(config);
+    }
+
+    @Nullable
+    public static PluginFileType<?, ?> guessType(JarFile file) {
+        for (PluginFileType<?, ?> type : VALUES) {
+            JarEntry entry = file.getJarEntry(type.config);
+            if (entry != null) {
+                return type;
+            }
+        }
+
+        return null;
+    }
+
+    public T register(EntrypointHandler entrypointHandler, JarFile file, Path context) throws Exception {
+        C config = this.getConfig(file);
+        T provider = this.factory.build(file, config, context);
+        this.register(entrypointHandler, provider);
+        return provider;
+    }
+
+    public C getConfig(JarFile file) throws Exception {
+        return this.factory.create(file, file.getJarEntry(this.config));
+    }
+
+    protected abstract void register(EntrypointHandler entrypointHandler, T provider);
+
+    public static List<String> getConfigTypes() {
+        return CONFIG_TYPES;
+    }
+}

paper-server/src/main/java/io/papermc/paper/plugin/provider/type/PluginTypeFactory.java

@@ -0,0 +1,21 @@
+package io.papermc.paper.plugin.provider.type;
+
+import io.papermc.paper.plugin.configuration.PluginMeta;
+
+import java.nio.file.Path;
+import java.util.jar.JarEntry;
+import java.util.jar.JarFile;
+
+/**
+ * A plugin type factory is responsible for building an object
+ * and config for a certain plugin type.
+ *
+ * @param <T> plugin provider type (may not be a plugin provider)
+ * @param <C> config type
+ */
+public interface PluginTypeFactory<T, C extends PluginMeta> {
+
+    T build(JarFile file, C configuration, Path source) throws Exception;
+
+    C create(JarFile file, JarEntry config) throws Exception;
+}

paper-server/src/main/java/io/papermc/paper/plugin/provider/type/paper/PaperBootstrapOrderConfiguration.java

@@ -0,0 +1,50 @@
+package io.papermc.paper.plugin.provider.type.paper;
+
+import io.papermc.paper.plugin.configuration.PluginMeta;
+import io.papermc.paper.plugin.provider.configuration.LoadOrderConfiguration;
+import io.papermc.paper.plugin.provider.configuration.PaperPluginMeta;
+import io.papermc.paper.plugin.provider.configuration.type.DependencyConfiguration;
+import org.jetbrains.annotations.NotNull;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Map;
+
+public class PaperBootstrapOrderConfiguration implements LoadOrderConfiguration {
+
+    private final PaperPluginMeta paperPluginMeta;
+    private final List<String> loadBefore = new ArrayList<>();
+    private final List<String> loadAfter = new ArrayList<>();
+
+    public PaperBootstrapOrderConfiguration(PaperPluginMeta paperPluginMeta) {
+        this.paperPluginMeta = paperPluginMeta;
+
+        for (Map.Entry<String, DependencyConfiguration> configuration : paperPluginMeta.getBootstrapDependencies().entrySet()) {
+            String name = configuration.getKey();
+            DependencyConfiguration dependencyConfiguration = configuration.getValue();
+
+            if (dependencyConfiguration.load() == DependencyConfiguration.LoadOrder.AFTER) {
+                // This plugin will load BEFORE all dependencies (so dependencies will load AFTER plugin)
+                this.loadBefore.add(name);
+            } else if (dependencyConfiguration.load() == DependencyConfiguration.LoadOrder.BEFORE) {
+                // This plugin will load AFTER all dependencies (so dependencies will load BEFORE plugin)
+                this.loadAfter.add(name);
+            }
+        }
+    }
+
+    @Override
+    public @NotNull List<String> getLoadBefore() {
+        return this.loadBefore;
+    }
+
+    @Override
+    public @NotNull List<String> getLoadAfter() {
+        return this.loadAfter;
+    }
+
+    @Override
+    public @NotNull PluginMeta getMeta() {
+        return this.paperPluginMeta;
+    }
+}

paper-server/src/main/java/io/papermc/paper/plugin/provider/type/paper/PaperLoadOrderConfiguration.java

@@ -0,0 +1,44 @@
+package io.papermc.paper.plugin.provider.type.paper;
+
+import io.papermc.paper.plugin.configuration.PluginMeta;
+import io.papermc.paper.plugin.provider.PluginProvider;
+import io.papermc.paper.plugin.provider.configuration.LoadOrderConfiguration;
+import io.papermc.paper.plugin.provider.configuration.PaperPluginMeta;
+import io.papermc.paper.plugin.provider.type.spigot.SpigotPluginProvider;
+import org.bukkit.plugin.PluginDescriptionFile;
+import org.bukkit.plugin.java.JavaPlugin;
+import org.jetbrains.annotations.NotNull;
+
+import java.util.ArrayList;
+import java.util.Iterator;
+import java.util.List;
+import java.util.Map;
+
+public class PaperLoadOrderConfiguration implements LoadOrderConfiguration {
+
+    private final PaperPluginMeta meta;
+    private final List<String> loadBefore;
+    private final List<String> loadAfter;
+
+    public PaperLoadOrderConfiguration(PaperPluginMeta meta) {
+        this.meta = meta;
+
+        this.loadBefore = this.meta.getLoadBeforePlugins();
+        this.loadAfter = this.meta.getLoadAfterPlugins();
+    }
+
+    @Override
+    public @NotNull List<String> getLoadBefore() {
+        return this.loadBefore;
+    }
+
+    @Override
+    public @NotNull List<String> getLoadAfter() {
+        return this.loadAfter;
+    }
+
+    @Override
+    public @NotNull PluginMeta getMeta() {
+        return this.meta;
+    }
+}

paper-server/src/main/java/io/papermc/paper/plugin/provider/type/paper/PaperPluginParent.java

@@ -0,0 +1,264 @@
+package io.papermc.paper.plugin.provider.type.paper;
+
+import com.destroystokyo.paper.util.SneakyThrow;
+import io.papermc.paper.plugin.bootstrap.PluginProviderContext;
+import io.papermc.paper.plugin.provider.configuration.LoadOrderConfiguration;
+import io.papermc.paper.plugin.provider.configuration.type.DependencyConfiguration;
+import io.papermc.paper.plugin.provider.entrypoint.DependencyContext;
+import io.papermc.paper.plugin.entrypoint.dependency.DependencyContextHolder;
+import io.papermc.paper.plugin.bootstrap.PluginBootstrap;
+import io.papermc.paper.plugin.entrypoint.classloader.PaperPluginClassLoader;
+import io.papermc.paper.plugin.provider.PluginProvider;
+import io.papermc.paper.plugin.provider.ProviderStatus;
+import io.papermc.paper.plugin.provider.ProviderStatusHolder;
+import io.papermc.paper.plugin.provider.configuration.PaperPluginMeta;
+import io.papermc.paper.plugin.provider.type.PluginTypeFactory;
+import io.papermc.paper.plugin.provider.util.ProviderUtil;
+import net.kyori.adventure.text.logger.slf4j.ComponentLogger;
+import org.bukkit.plugin.java.JavaPlugin;
+import org.jetbrains.annotations.NotNull;
+
+import java.nio.file.Path;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Map;
+import java.util.jar.JarFile;
+
+public class PaperPluginParent {
+
+    public static final PluginTypeFactory<PaperPluginParent, PaperPluginMeta> FACTORY = new PaperPluginProviderFactory();
+    private final Path path;
+    private final JarFile jarFile;
+    private final PaperPluginMeta description;
+    private final PaperPluginClassLoader classLoader;
+    private final PluginProviderContext context;
+    private final ComponentLogger logger;
+
+    public PaperPluginParent(Path path, JarFile jarFile, PaperPluginMeta description, PaperPluginClassLoader classLoader, PluginProviderContext context) {
+        this.path = path;
+        this.jarFile = jarFile;
+        this.description = description;
+        this.classLoader = classLoader;
+        this.context = context;
+        this.logger = context.getLogger();
+    }
+
+    public boolean shouldCreateBootstrap() {
+        return this.description.getBootstrapper() != null;
+    }
+
+    public PaperBootstrapProvider createBootstrapProvider() {
+        return new PaperBootstrapProvider();
+    }
+
+    public PaperServerPluginProvider createPluginProvider(PaperBootstrapProvider provider) {
+        return new PaperServerPluginProvider(provider);
+    }
+
+    public class PaperBootstrapProvider implements PluginProvider<PluginBootstrap>, ProviderStatusHolder, DependencyContextHolder {
+
+        private ProviderStatus status;
+        private PluginBootstrap lastProvided;
+
+        @Override
+        public @NotNull Path getSource() {
+            return PaperPluginParent.this.path;
+        }
+
+        @Override
+        public JarFile file() {
+            return PaperPluginParent.this.jarFile;
+        }
+
+        @Override
+        public PluginBootstrap createInstance() {
+            PluginBootstrap bootstrap = ProviderUtil.loadClass(PaperPluginParent.this.description.getBootstrapper(),
+                PluginBootstrap.class, PaperPluginParent.this.classLoader, () -> this.status = ProviderStatus.ERRORED);
+            this.status = ProviderStatus.INITIALIZED;
+            this.lastProvided = bootstrap;
+            return bootstrap;
+        }
+
+        @Override
+        public PaperPluginMeta getMeta() {
+            return PaperPluginParent.this.description;
+        }
+
+        @Override
+        public ComponentLogger getLogger() {
+            return PaperPluginParent.this.logger;
+        }
+
+        @Override
+        public LoadOrderConfiguration createConfiguration(@NotNull Map<String, PluginProvider<?>> toLoad) {
+            return new PaperBootstrapOrderConfiguration(PaperPluginParent.this.description);
+        }
+
+        @Override
+        public List<String> validateDependencies(@NotNull DependencyContext context) {
+            List<String> missingDependencies = new ArrayList<>();
+            for (Map.Entry<String, DependencyConfiguration> configuration : this.getMeta().getBootstrapDependencies().entrySet()) {
+                String dependency = configuration.getKey();
+                if (configuration.getValue().required() && !context.hasDependency(dependency)) {
+                    missingDependencies.add(dependency);
+                }
+            }
+
+            return missingDependencies;
+        }
+
+        @Override
+        public ProviderStatus getLastProvidedStatus() {
+            return this.status;
+        }
+
+        @Override
+        public void setStatus(ProviderStatus status) {
+            this.status = status;
+        }
+
+        public PluginBootstrap getLastProvided() {
+            return this.lastProvided;
+        }
+
+        @Override
+        public void setContext(DependencyContext context) {
+            PaperPluginParent.this.classLoader.refreshClassloaderDependencyTree(context);
+        }
+
+        @Override
+        public String toString() {
+            return "PaperBootstrapProvider{" +
+                "parent=" + PaperPluginParent.this +
+                "status=" + status +
+                ", lastProvided=" + lastProvided +
+                '}';
+        }
+    }
+
+    public class PaperServerPluginProvider implements PluginProvider<JavaPlugin>, ProviderStatusHolder, DependencyContextHolder {
+
+        private final PaperBootstrapProvider bootstrapProvider;
+
+        private ProviderStatus status;
+
+        PaperServerPluginProvider(PaperBootstrapProvider bootstrapProvider) {
+            this.bootstrapProvider = bootstrapProvider;
+        }
+
+        @Override
+        public @NotNull Path getSource() {
+            return PaperPluginParent.this.path;
+        }
+
+        @Override
+        public JarFile file() {
+            return PaperPluginParent.this.jarFile;
+        }
+
+        @Override
+        public JavaPlugin createInstance() {
+            PluginBootstrap bootstrap = null;
+            if (this.bootstrapProvider != null && this.bootstrapProvider.getLastProvided() != null) {
+                bootstrap = this.bootstrapProvider.getLastProvided();
+            }
+
+            try {
+                JavaPlugin plugin;
+                if (bootstrap == null) {
+                    plugin = ProviderUtil.loadClass(PaperPluginParent.this.description.getMainClass(), JavaPlugin.class, PaperPluginParent.this.classLoader);
+                } else {
+                    plugin = bootstrap.createPlugin(PaperPluginParent.this.context);
+                }
+
+                if (!plugin.getClass().isAssignableFrom(Class.forName(PaperPluginParent.this.description.getMainClass(), true, plugin.getClass().getClassLoader()))) {
+                    logger.info("Bootstrap of plugin " + PaperPluginParent.this.description.getName() + " provided a plugin instance of class " + plugin.getClass().getName() + " which does not match the plugin declared main class");
+                }
+
+                this.status = ProviderStatus.INITIALIZED;
+                return plugin;
+            } catch (Throwable throwable) {
+                this.status = ProviderStatus.ERRORED;
+                SneakyThrow.sneaky(throwable);
+            }
+
+            throw new AssertionError(); // Impossible
+        }
+
+        @Override
+        public PaperPluginMeta getMeta() {
+            return PaperPluginParent.this.description;
+        }
+
+        @Override
+        public ComponentLogger getLogger() {
+            return PaperPluginParent.this.logger;
+        }
+
+        @Override
+        public LoadOrderConfiguration createConfiguration(@NotNull Map<String, PluginProvider<?>> toLoad) {
+            return new PaperLoadOrderConfiguration(PaperPluginParent.this.description);
+        }
+
+        @Override
+        public List<String> validateDependencies(@NotNull DependencyContext context) {
+            List<String> missingDependencies = new ArrayList<>();
+            for (Map.Entry<String, DependencyConfiguration> dependency : this.getMeta().getServerDependencies().entrySet()) {
+                String name = dependency.getKey();
+                if (dependency.getValue().required() && !context.hasDependency(name)) {
+                    missingDependencies.add(name);
+                }
+            }
+
+            return missingDependencies;
+        }
+
+        @Override
+        public ProviderStatus getLastProvidedStatus() {
+            return this.status;
+        }
+
+        @Override
+        public void setStatus(ProviderStatus status) {
+            this.status = status;
+        }
+
+        public boolean shouldSkipCreation() {
+            if (this.bootstrapProvider == null) {
+                return false;
+            }
+
+            return this.bootstrapProvider.getLastProvidedStatus() == ProviderStatus.ERRORED;
+        }
+
+        /*
+        The plugin has to reuse the classloader in order to share the bootstrapper.
+        However, a plugin may have totally separate dependencies during bootstrapping.
+        This is a bit yuck, but in general we have to treat bootstrapping and normal game as connected.
+         */
+        @Override
+        public void setContext(DependencyContext context) {
+            PaperPluginParent.this.classLoader.refreshClassloaderDependencyTree(context);
+        }
+
+        @Override
+        public String toString() {
+            return "PaperServerPluginProvider{" +
+                "parent=" + PaperPluginParent.this +
+                "bootstrapProvider=" + bootstrapProvider +
+                ", status=" + status +
+                '}';
+        }
+    }
+
+
+    @Override
+    public String toString() {
+        return "PaperPluginParent{" +
+            "path=" + path +
+            ", jarFile=" + jarFile +
+            ", description=" + description +
+            ", classLoader=" + classLoader +
+            '}';
+    }
+}

paper-server/src/main/java/io/papermc/paper/plugin/provider/type/paper/PaperPluginProviderFactory.java

@@ -0,0 +1,56 @@
+package io.papermc.paper.plugin.provider.type.paper;
+
+import com.destroystokyo.paper.utils.PaperPluginLogger;
+import io.papermc.paper.plugin.bootstrap.PluginProviderContext;
+import io.papermc.paper.plugin.bootstrap.PluginProviderContextImpl;
+import io.papermc.paper.plugin.entrypoint.classloader.PaperPluginClassLoader;
+import io.papermc.paper.plugin.entrypoint.classloader.PaperSimplePluginClassLoader;
+import io.papermc.paper.plugin.loader.PaperClasspathBuilder;
+import io.papermc.paper.plugin.loader.PluginLoader;
+import io.papermc.paper.plugin.provider.configuration.PaperPluginMeta;
+import io.papermc.paper.plugin.provider.type.PluginTypeFactory;
+import io.papermc.paper.plugin.provider.util.ProviderUtil;
+
+import java.io.BufferedReader;
+import java.io.IOException;
+import java.io.InputStreamReader;
+import java.nio.file.Path;
+import java.util.jar.JarEntry;
+import java.util.jar.JarFile;
+import java.util.logging.Logger;
+import net.kyori.adventure.text.logger.slf4j.ComponentLogger;
+
+class PaperPluginProviderFactory implements PluginTypeFactory<PaperPluginParent, PaperPluginMeta> {
+
+    @Override
+    public PaperPluginParent build(JarFile file, PaperPluginMeta configuration, Path source) {
+        Logger jul = PaperPluginLogger.getLogger(configuration);
+        ComponentLogger logger = ComponentLogger.logger(jul.getName());
+        PluginProviderContext context = PluginProviderContextImpl.create(configuration, logger, source);
+
+        PaperClasspathBuilder builder = new PaperClasspathBuilder(context);
+
+        if (configuration.getLoader() != null) {
+            try (
+                PaperSimplePluginClassLoader simplePluginClassLoader = new PaperSimplePluginClassLoader(source, file, configuration, this.getClass().getClassLoader())
+            ) {
+                PluginLoader loader = ProviderUtil.loadClass(configuration.getLoader(), PluginLoader.class, simplePluginClassLoader);
+                loader.classloader(builder);
+            } catch (IOException e) {
+                throw new RuntimeException(e);
+            }
+        }
+
+        PaperPluginClassLoader classLoader = builder.buildClassLoader(jul, source, file, configuration);
+        return new PaperPluginParent(source, file, configuration, classLoader, context);
+    }
+
+    @Override
+    public PaperPluginMeta create(JarFile file, JarEntry config) throws IOException {
+        PaperPluginMeta configuration;
+        try (BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(file.getInputStream(config)))) {
+            configuration = PaperPluginMeta.create(bufferedReader);
+        }
+        return configuration;
+    }
+}

paper-server/src/main/java/io/papermc/paper/plugin/provider/type/spigot/SpigotLoadOrderConfiguration.java

@@ -0,0 +1,72 @@
+package io.papermc.paper.plugin.provider.type.spigot;
+
+import io.papermc.paper.plugin.configuration.PluginMeta;
+import io.papermc.paper.plugin.provider.PluginProvider;
+import io.papermc.paper.plugin.provider.configuration.LoadOrderConfiguration;
+import org.bukkit.plugin.PluginDescriptionFile;
+import org.bukkit.plugin.java.JavaPlugin;
+import org.jetbrains.annotations.NotNull;
+
+import java.util.ArrayList;
+import java.util.HashSet;
+import java.util.Iterator;
+import java.util.List;
+import java.util.Map;
+import java.util.Set;
+
+public class SpigotLoadOrderConfiguration implements LoadOrderConfiguration {
+
+    private final PluginDescriptionFile meta;
+    private final List<String> loadBefore;
+    private final List<String> loadAfter;
+
+    public SpigotLoadOrderConfiguration(SpigotPluginProvider spigotPluginProvider, Map<String, PluginProvider<?>> toLoad) {
+        this.meta = spigotPluginProvider.getMeta();
+
+        this.loadBefore = meta.getLoadBeforePlugins();
+        this.loadAfter = new ArrayList<>();
+        this.loadAfter.addAll(meta.getDepend());
+        this.loadAfter.addAll(meta.getSoftDepend());
+
+        // First: Remove as load after IF already in loadbefore
+        // Some plugins would put a plugin both in depends and in loadbefore,
+        // so in this case, we just ignore the effects of depend.
+        for (String loadBefore : this.loadBefore) {
+            this.loadAfter.remove(loadBefore);
+        }
+
+        // Second: Do a basic check to see if any other dependencies refer back to this plugin.
+        Iterator<String> iterators = this.loadAfter.iterator();
+        while (iterators.hasNext()) {
+            String loadAfter = iterators.next();
+            PluginProvider<?> provider = toLoad.get(loadAfter);
+            if (provider != null) {
+                PluginMeta configuration = provider.getMeta();
+                // Does a configuration refer back to this plugin?
+                Set<String> dependencies = new HashSet<>();
+                dependencies.addAll(configuration.getPluginDependencies());
+                dependencies.addAll(configuration.getPluginSoftDependencies());
+
+                if (configuration.getName().equals(this.meta.getName()) || dependencies.contains(this.meta.getName())) {
+                    iterators.remove(); // Let the other config deal with it
+                }
+            }
+        }
+
+    }
+
+    @Override
+    public @NotNull List<String> getLoadBefore() {
+        return this.loadBefore;
+    }
+
+    @Override
+    public @NotNull List<String> getLoadAfter() {
+        return this.loadAfter;
+    }
+
+    @Override
+    public @NotNull PluginMeta getMeta() {
+        return this.meta;
+    }
+}

paper-server/src/main/java/io/papermc/paper/plugin/provider/type/spigot/SpigotPluginProvider.java

@@ -0,0 +1,197 @@
+package io.papermc.paper.plugin.provider.type.spigot;
+
+import com.destroystokyo.paper.util.SneakyThrow;
+import com.destroystokyo.paper.utils.PaperPluginLogger;
+import io.papermc.paper.plugin.manager.PaperPluginManagerImpl;
+import io.papermc.paper.plugin.provider.configuration.LoadOrderConfiguration;
+import io.papermc.paper.plugin.provider.entrypoint.DependencyContext;
+import io.papermc.paper.plugin.entrypoint.dependency.DependencyContextHolder;
+import io.papermc.paper.plugin.provider.PluginProvider;
+import io.papermc.paper.plugin.provider.ProviderStatus;
+import io.papermc.paper.plugin.provider.ProviderStatusHolder;
+import io.papermc.paper.plugin.provider.type.PluginTypeFactory;
+import net.kyori.adventure.text.logger.slf4j.ComponentLogger;
+import org.bukkit.Bukkit;
+import org.bukkit.Server;
+import org.bukkit.plugin.InvalidPluginException;
+import org.bukkit.plugin.PluginDescriptionFile;
+import org.bukkit.plugin.UnknownDependencyException;
+import org.bukkit.plugin.java.JavaPlugin;
+import org.bukkit.plugin.java.LibraryLoader;
+import org.bukkit.plugin.java.PluginClassLoader;
+import org.jetbrains.annotations.NotNull;
+
+import java.io.File;
+import java.nio.file.Path;
+import java.util.ArrayList;
+import java.util.HashSet;
+import java.util.List;
+import java.util.Map;
+import java.util.Set;
+import java.util.jar.JarFile;
+import java.util.logging.Level;
+import java.util.logging.Logger;
+
+public class SpigotPluginProvider implements PluginProvider<JavaPlugin>, ProviderStatusHolder, DependencyContextHolder {
+
+    public static final PluginTypeFactory<SpigotPluginProvider, PluginDescriptionFile> FACTORY = new SpigotPluginProviderFactory();
+    private static final LibraryLoader LIBRARY_LOADER = new LibraryLoader(Logger.getLogger("SpigotLibraryLoader"));
+    private final Path path;
+    private final PluginDescriptionFile description;
+    private final JarFile jarFile;
+    private final Logger logger;
+    private final ComponentLogger componentLogger;
+    private ProviderStatus status;
+    private DependencyContext dependencyContext;
+
+    SpigotPluginProvider(Path path, JarFile file, PluginDescriptionFile description) {
+        this.path = path;
+        this.jarFile = file;
+        this.description = description;
+        this.logger = PaperPluginLogger.getLogger(description);
+        this.componentLogger = ComponentLogger.logger(this.logger.getName());
+    }
+
+    @Override
+    public @NotNull Path getSource() {
+        return this.path;
+    }
+
+    @Override
+    public JarFile file() {
+        return this.jarFile;
+    }
+
+    @Override
+    public JavaPlugin createInstance() {
+        Server server = Bukkit.getServer();
+        try {
+
+            final File parentFile = server.getPluginsFolder(); // Paper
+            final File dataFolder = new File(parentFile, this.description.getName());
+            @SuppressWarnings("deprecation") final File oldDataFolder = new File(parentFile, this.description.getRawName());
+
+            // Found old data folder
+            if (dataFolder.equals(oldDataFolder)) {
+                // They are equal -- nothing needs to be done!
+            } else if (dataFolder.isDirectory() && oldDataFolder.isDirectory()) {
+                server.getLogger().warning(String.format(
+                    "While loading %s (%s) found old-data folder: `%s' next to the new one `%s'",
+                    this.description.getFullName(),
+                    this.path,
+                    oldDataFolder,
+                    dataFolder
+                ));
+            } else if (oldDataFolder.isDirectory() && !dataFolder.exists()) {
+                if (!oldDataFolder.renameTo(dataFolder)) {
+                    throw new InvalidPluginException("Unable to rename old data folder: `" + oldDataFolder + "' to: `" + dataFolder + "'");
+                }
+                server.getLogger().log(Level.INFO, String.format(
+                    "While loading %s (%s) renamed data folder: `%s' to `%s'",
+                    this.description.getFullName(),
+                    this.path,
+                    oldDataFolder,
+                    dataFolder
+                ));
+            }
+
+            if (dataFolder.exists() && !dataFolder.isDirectory()) {
+                throw new InvalidPluginException(String.format(
+                    "Projected datafolder: `%s' for %s (%s) exists and is not a directory",
+                    dataFolder,
+                    this.description.getFullName(),
+                    this.path
+                ));
+            }
+
+            Set<String> missingHardDependencies = new HashSet<>(this.description.getDepend().size()); // Paper - list all missing hard depends
+            for (final String pluginName : this.description.getDepend()) {
+                if (!this.dependencyContext.hasDependency(pluginName)) {
+                    missingHardDependencies.add(pluginName); // Paper - list all missing hard depends
+                }
+            }
+            // Paper start - list all missing hard depends
+            if (!missingHardDependencies.isEmpty()) {
+                throw new UnknownDependencyException(missingHardDependencies, this.description.getFullName());
+            }
+            // Paper end
+
+            server.getUnsafe().checkSupported(this.description);
+
+            final PluginClassLoader loader;
+            try {
+                loader = new PluginClassLoader(this.getClass().getClassLoader(), this.description, dataFolder, this.path.toFile(), LIBRARY_LOADER.createLoader(this.description), this.jarFile, this.dependencyContext); // Paper
+            } catch (InvalidPluginException ex) {
+                throw ex;
+            } catch (Throwable ex) {
+                throw new InvalidPluginException(ex);
+            }
+
+            // Override dependency context.
+            // We must provide a temporary context in order to properly handle dependencies on the plugin classloader constructor.
+            loader.dependencyContext = PaperPluginManagerImpl.getInstance();
+
+
+            this.status = ProviderStatus.INITIALIZED;
+            return loader.getPlugin();
+        } catch (Throwable ex) {
+            this.status = ProviderStatus.ERRORED;
+            SneakyThrow.sneaky(ex);
+        }
+
+        throw new AssertionError(); // Shouldn't happen
+    }
+
+    @Override
+    public PluginDescriptionFile getMeta() {
+        return this.description;
+    }
+
+    @Override
+    public ComponentLogger getLogger() {
+        return this.componentLogger;
+    }
+
+    @Override
+    public LoadOrderConfiguration createConfiguration(@NotNull Map<String, PluginProvider<?>> toLoad) {
+        return new SpigotLoadOrderConfiguration(this, toLoad);
+    }
+
+    @Override
+    public List<String> validateDependencies(@NotNull DependencyContext context) {
+        List<String> missingDependencies = new ArrayList<>();
+        for (String hardDependency : this.getMeta().getPluginDependencies()) {
+            if (!context.hasDependency(hardDependency)) {
+                missingDependencies.add(hardDependency);
+            }
+        }
+
+        return missingDependencies;
+    }
+
+    @Override
+    public ProviderStatus getLastProvidedStatus() {
+        return this.status;
+    }
+
+    @Override
+    public void setStatus(ProviderStatus status) {
+        this.status = status;
+    }
+
+    @Override
+    public void setContext(DependencyContext context) {
+        this.dependencyContext = context;
+    }
+
+    @Override
+    public String toString() {
+        return "SpigotPluginProvider{" +
+            "path=" + path +
+            ", description=" + description +
+            ", jarFile=" + jarFile +
+            ", status=" + status +
+            ", dependencyContext=" + dependencyContext +
+            '}';
+    }
+}

paper-server/src/main/java/io/papermc/paper/plugin/provider/type/spigot/SpigotPluginProviderFactory.java

@@ -0,0 +1,45 @@
+package io.papermc.paper.plugin.provider.type.spigot;
+
+import io.papermc.paper.plugin.provider.configuration.serializer.constraints.PluginConfigConstraints;
+import io.papermc.paper.plugin.provider.type.PluginTypeFactory;
+import org.bukkit.plugin.InvalidDescriptionException;
+import org.bukkit.plugin.PluginDescriptionFile;
+import org.yaml.snakeyaml.error.YAMLException;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.nio.file.Path;
+import java.util.Locale;
+import java.util.jar.JarEntry;
+import java.util.jar.JarFile;
+
+class SpigotPluginProviderFactory implements PluginTypeFactory<SpigotPluginProvider, PluginDescriptionFile> {
+
+    @Override
+    public SpigotPluginProvider build(JarFile file, PluginDescriptionFile configuration, Path source) throws InvalidDescriptionException {
+        // Copied from SimplePluginManager#loadPlugins
+        // Spigot doesn't validate the name when the config is created, and instead when the plugin is loaded.
+        // Paper plugin configuration will do these checks in config serializer instead of when this is created.
+        String name = configuration.getRawName();
+        if (PluginConfigConstraints.RESERVED_KEYS.contains(name.toLowerCase(Locale.ROOT))) {
+            throw new InvalidDescriptionException("Restricted name, cannot use %s as a plugin name.".formatted(name));
+        } else if (name.indexOf(' ') != -1) {
+            throw new InvalidDescriptionException("Restricted name, cannot use 0x20 (space character) in a plugin name.");
+        }
+
+        return new SpigotPluginProvider(source, file, configuration);
+    }
+
+    @Override
+    public PluginDescriptionFile create(JarFile file, JarEntry config) throws InvalidDescriptionException {
+        PluginDescriptionFile descriptionFile;
+        try (InputStream inputStream = file.getInputStream(config)) {
+            descriptionFile = new PluginDescriptionFile(inputStream);
+        } catch (IOException | YAMLException ex) {
+            throw new InvalidDescriptionException(ex);
+        }
+
+        return descriptionFile;
+    }
+}
+

paper-server/src/main/java/io/papermc/paper/plugin/storage/BootstrapProviderStorage.java

@@ -0,0 +1,65 @@
+package io.papermc.paper.plugin.storage;
+
+import com.mojang.logging.LogUtils;
+import io.papermc.paper.plugin.PluginInitializerManager;
+import io.papermc.paper.plugin.bootstrap.BootstrapContext;
+import io.papermc.paper.plugin.bootstrap.PluginBootstrap;
+import io.papermc.paper.plugin.bootstrap.PluginBootstrapContextImpl;
+import io.papermc.paper.plugin.entrypoint.dependency.BootstrapMetaDependencyTree;
+import io.papermc.paper.plugin.entrypoint.dependency.DependencyContextHolder;
+import io.papermc.paper.plugin.entrypoint.dependency.MetaDependencyTree;
+import io.papermc.paper.plugin.entrypoint.strategy.ProviderConfiguration;
+import io.papermc.paper.plugin.entrypoint.strategy.modern.ModernPluginLoadingStrategy;
+import io.papermc.paper.plugin.provider.PluginProvider;
+import io.papermc.paper.plugin.provider.ProviderStatus;
+import io.papermc.paper.plugin.provider.ProviderStatusHolder;
+import io.papermc.paper.plugin.provider.entrypoint.DependencyContext;
+import org.slf4j.Logger;
+
+public class BootstrapProviderStorage extends SimpleProviderStorage<PluginBootstrap> {
+
+    private static final Logger LOGGER = LogUtils.getClassLogger();
+
+    public BootstrapProviderStorage() {
+        super(new ModernPluginLoadingStrategy<>(new ProviderConfiguration<>() {
+            @Override
+            public void applyContext(PluginProvider<PluginBootstrap> provider, DependencyContext dependencyContext) {
+                if (provider instanceof DependencyContextHolder contextHolder) {
+                    contextHolder.setContext(dependencyContext);
+                }
+            }
+
+            @Override
+            public boolean load(PluginProvider<PluginBootstrap> provider, PluginBootstrap provided) {
+                try {
+                    BootstrapContext context = PluginBootstrapContextImpl.create(provider, PluginInitializerManager.instance().pluginDirectoryPath());
+                    provided.bootstrap(context);
+                    return true;
+                } catch (Throwable e) {
+                    LOGGER.error("Failed to run bootstrapper for %s. This plugin will not be loaded.".formatted(provider.getSource()), e);
+                    if (provider instanceof ProviderStatusHolder statusHolder) {
+                        statusHolder.setStatus(ProviderStatus.ERRORED);
+                    }
+                    return false;
+                }
+            }
+
+            @Override
+            public void onGenericError(PluginProvider<PluginBootstrap> provider) {
+                if (provider instanceof ProviderStatusHolder statusHolder) {
+                    statusHolder.setStatus(ProviderStatus.ERRORED);
+                }
+            }
+        }));
+    }
+
+    @Override
+    public MetaDependencyTree createDependencyTree() {
+        return new BootstrapMetaDependencyTree();
+    }
+
+    @Override
+    public String toString() {
+        return "BOOTSTRAP:" + super.toString();
+    }
+}

paper-server/src/main/java/io/papermc/paper/plugin/storage/ConfiguredProviderStorage.java

@@ -0,0 +1,17 @@
+package io.papermc.paper.plugin.storage;
+
+import io.papermc.paper.plugin.entrypoint.strategy.LegacyPluginLoadingStrategy;
+import io.papermc.paper.plugin.entrypoint.strategy.modern.ModernPluginLoadingStrategy;
+import io.papermc.paper.plugin.entrypoint.strategy.ProviderConfiguration;
+
+public abstract class ConfiguredProviderStorage<T> extends SimpleProviderStorage<T> {
+
+    public static final boolean LEGACY_PLUGIN_LOADING = Boolean.getBoolean("paper.useLegacyPluginLoading");
+
+    protected ConfiguredProviderStorage(ProviderConfiguration<T> onLoad) {
+        // This doesn't work with reloading.
+        // Should we care?
+        super(LEGACY_PLUGIN_LOADING ? new LegacyPluginLoadingStrategy<>(onLoad) : new ModernPluginLoadingStrategy<>(onLoad));
+    }
+
+}

paper-server/src/main/java/io/papermc/paper/plugin/storage/ProviderStorage.java

@@ -0,0 +1,21 @@
+package io.papermc.paper.plugin.storage;
+
+import io.papermc.paper.plugin.entrypoint.dependency.MetaDependencyTree;
+import io.papermc.paper.plugin.provider.PluginProvider;
+
+/**
+ * A provider storage is meant to be a singleton that stores providers.
+ *
+ * @param <T> provider type
+ */
+public interface ProviderStorage<T> {
+
+    void register(PluginProvider<T> provider);
+
+    MetaDependencyTree createDependencyTree();
+
+    void enter();
+
+    Iterable<PluginProvider<T>> getRegisteredProviders();
+
+}

paper-server/src/main/java/io/papermc/paper/plugin/storage/ServerPluginProviderStorage.java

@@ -0,0 +1,70 @@
+package io.papermc.paper.plugin.storage;
+
+import com.mojang.logging.LogUtils;
+import io.papermc.paper.plugin.provider.entrypoint.DependencyContext;
+import io.papermc.paper.plugin.entrypoint.dependency.DependencyContextHolder;
+import io.papermc.paper.plugin.entrypoint.strategy.ProviderConfiguration;
+import io.papermc.paper.plugin.manager.PaperPluginManagerImpl;
+import io.papermc.paper.plugin.provider.PluginProvider;
+import io.papermc.paper.plugin.provider.ProviderStatus;
+import io.papermc.paper.plugin.provider.ProviderStatusHolder;
+import io.papermc.paper.plugin.provider.type.paper.PaperPluginParent;
+import org.bukkit.plugin.Plugin;
+import org.bukkit.plugin.java.JavaPlugin;
+import org.slf4j.Logger;
+
+import java.util.List;
+
+public class ServerPluginProviderStorage extends ConfiguredProviderStorage<JavaPlugin> {
+
+    private static final Logger LOGGER = LogUtils.getClassLogger();
+
+    public ServerPluginProviderStorage() {
+        super(new ProviderConfiguration<>() {
+            @Override
+            public void applyContext(PluginProvider<JavaPlugin> provider, DependencyContext dependencyContext) {
+                Plugin alreadyLoadedPlugin = PaperPluginManagerImpl.getInstance().getPlugin(provider.getMeta().getName());
+                if (alreadyLoadedPlugin != null) {
+                    throw new IllegalStateException("Provider " + provider + " attempted to add duplicate plugin identifier " + alreadyLoadedPlugin + " THIS WILL CREATE BUGS!!!");
+                }
+
+                if (provider instanceof DependencyContextHolder contextHolder) {
+                    contextHolder.setContext(dependencyContext);
+                }
+            }
+
+            @Override
+            public boolean load(PluginProvider<JavaPlugin> provider, JavaPlugin provided) {
+                // Add it to the map here, we have to run the actual loading logic later.
+                PaperPluginManagerImpl.getInstance().loadPlugin(provided);
+                return true;
+            }
+        });
+    }
+
+    @Override
+    protected void filterLoadingProviders(List<PluginProvider<JavaPlugin>> pluginProviders) {
+         /*
+        Have to do this to prevent loading plugin providers that have failed initializers.
+        This is a hack and a better solution here would be to store failed plugin providers elsewhere.
+         */
+        pluginProviders.removeIf((provider) -> (provider instanceof PaperPluginParent.PaperServerPluginProvider pluginProvider && pluginProvider.shouldSkipCreation()));
+    }
+
+    // We need to call the load methods AFTER all plugins are constructed
+    @Override
+    public void processProvided(PluginProvider<JavaPlugin> provider, JavaPlugin provided) {
+        try {
+            provided.getLogger().info(String.format("Loading server plugin %s", provided.getPluginMeta().getDisplayName()));
+            provided.onLoad();
+        } catch (Throwable ex) {
+            // Don't mark that provider as ERRORED, as this apparently still needs to run the onEnable logic.
+            provided.getSLF4JLogger().error("Error initializing plugin '%s' in folder '%s' (Is it up to date?)".formatted(provider.getFileName(), provider.getParentSource()), ex);
+        }
+    }
+
+    @Override
+    public String toString() {
+        return "PLUGIN:" + super.toString();
+    }
+}

paper-server/src/main/java/io/papermc/paper/plugin/storage/SimpleProviderStorage.java

@@ -0,0 +1,93 @@
+package io.papermc.paper.plugin.storage;
+
+import com.google.common.graph.GraphBuilder;
+import com.mojang.logging.LogUtils;
+import io.papermc.paper.plugin.entrypoint.dependency.MetaDependencyTree;
+import io.papermc.paper.plugin.entrypoint.dependency.SimpleMetaDependencyTree;
+import io.papermc.paper.plugin.entrypoint.strategy.PluginGraphCycleException;
+import io.papermc.paper.plugin.entrypoint.strategy.ProviderLoadingStrategy;
+import io.papermc.paper.plugin.provider.PluginProvider;
+import org.slf4j.Logger;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.stream.Collectors;
+
+public abstract class SimpleProviderStorage<T> implements ProviderStorage<T> {
+
+    private static final Logger LOGGER = LogUtils.getClassLogger();
+
+    protected final List<PluginProvider<T>> providers = new ArrayList<>();
+    protected ProviderLoadingStrategy<T> strategy;
+
+    protected SimpleProviderStorage(ProviderLoadingStrategy<T> strategy) {
+        this.strategy = strategy;
+    }
+
+    @Override
+    public void register(PluginProvider<T> provider) {
+        this.providers.add(provider);
+    }
+
+    @Override
+    public void enter() {
+        List<PluginProvider<T>> providerList = new ArrayList<>(this.providers);
+        this.filterLoadingProviders(providerList);
+
+        try {
+            for (ProviderLoadingStrategy.ProviderPair<T> providerPair : this.strategy.loadProviders(providerList, this.createDependencyTree())) {
+                this.processProvided(providerPair.provider(), providerPair.provided());
+            }
+        } catch (PluginGraphCycleException exception) {
+            this.handleCycle(exception);
+        }
+    }
+
+    @Override
+    public MetaDependencyTree createDependencyTree() {
+        return new SimpleMetaDependencyTree(GraphBuilder.directed().build());
+    }
+
+    @Override
+    public Iterable<PluginProvider<T>> getRegisteredProviders() {
+        return this.providers;
+    }
+
+    public void processProvided(PluginProvider<T> provider, T provided) {
+    }
+
+    // Mutable enter
+    protected void filterLoadingProviders(List<PluginProvider<T>> providers) {
+    }
+
+    protected void handleCycle(PluginGraphCycleException exception) {
+        List<String> logMessages = new ArrayList<>();
+        for (List<String> list : exception.getCycles()) {
+            logMessages.add(String.join(" -> ", list) + " -> " + list.get(0));
+        }
+
+        LOGGER.error("Circular plugin loading detected!");
+        LOGGER.error("Circular load order:");
+        for (String logMessage : logMessages) {
+            LOGGER.error("  {}", logMessage);
+        }
+        LOGGER.error("Please report this to the plugin authors of the first plugin of each loop or join the PaperMC Discord server for further help.");
+        LOGGER.error("If you would like to still load these plugins, acknowledging that there may be unexpected plugin loading issues, run the server with -Dpaper.useLegacyPluginLoading=true");
+
+        if (this.throwOnCycle()) {
+            throw new IllegalStateException("Circular plugin loading from plugins " + exception.getCycles().stream().map(cycle -> cycle.get(0)).collect(Collectors.joining(", ")));
+        }
+    }
+
+    public boolean throwOnCycle() {
+        return true;
+    }
+
+    @Override
+    public String toString() {
+        return "SimpleProviderStorage{" +
+            "providers=" + this.providers +
+            ", strategy=" + this.strategy +
+            '}';
+    }
+}

paper-server/src/main/java/io/papermc/paper/plugin/storage/package-info.java

@@ -0,0 +1,5 @@
+/**
+ * Classes in this package are supposed to connect components of {@link io.papermc.paper.plugin.entrypoint} and {@link io.papermc.paper.plugin.provider} packages.
+ * @see io.papermc.paper.plugin.entrypoint.Entrypoint
+ */
+package io.papermc.paper.plugin.storage;

paper-server/src/main/java/io/papermc/paper/plugin/util/EntrypointUtil.java

@@ -0,0 +1,20 @@
+package io.papermc.paper.plugin.util;
+
+import com.mojang.logging.LogUtils;
+import io.papermc.paper.plugin.entrypoint.LaunchEntryPointHandler;
+import io.papermc.paper.plugin.provider.source.ProviderSource;
+import org.slf4j.Logger;
+
+public final class EntrypointUtil {
+
+    private static final Logger LOGGER = LogUtils.getClassLogger();
+
+    public static <I, C> void registerProvidersFromSource(ProviderSource<I, C> source, I contextInput) {
+        try {
+            C context = source.prepareContext(contextInput);
+            source.registerProviders(LaunchEntryPointHandler.INSTANCE, context);
+        } catch (Throwable e) {
+            LOGGER.error(e.getMessage(), e);
+        }
+    }
+}

paper-server/src/main/java/io/papermc/paper/plugin/util/NamespaceChecker.java

@@ -0,0 +1,37 @@
+package io.papermc.paper.plugin.util;
+
+import org.jetbrains.annotations.ApiStatus;
+import org.jetbrains.annotations.NotNull;
+
+@ApiStatus.Internal
+public class NamespaceChecker {
+
+    private static final String[] QUICK_INVALID_NAMESPACES = {
+        "net.minecraft.",
+        "org.bukkit.",
+        "io.papermc.paper.",
+        "com.destroystokoyo.paper."
+    };
+
+    /**
+     * Used for a variety of namespaces that shouldn't be resolved and should instead be moved to
+     * other classloaders. We can assume this because only plugins should be using this classloader.
+     *
+     * @param name namespace
+     */
+    public static void validateNameSpaceForClassloading(@NotNull String name) throws ClassNotFoundException {
+        if (!isValidNameSpace(name)) {
+            throw new ClassNotFoundException(name);
+        }
+    }
+
+    public static boolean isValidNameSpace(@NotNull String name) {
+        for (String string : QUICK_INVALID_NAMESPACES) {
+            if (name.startsWith(string)) {
+                return false;
+            }
+        }
+
+        return true;
+    }
+}

paper-server/src/main/java/io/papermc/paper/util/StackWalkerUtil.java

@@ -1,9 +1,10 @@
 package io.papermc.paper.util;
 
+import io.papermc.paper.plugin.provider.classloader.ConfiguredPluginClassLoader;
 import org.bukkit.plugin.java.JavaPlugin;
-import org.bukkit.plugin.java.PluginClassLoader;
 import org.jetbrains.annotations.Nullable;
 
+import java.util.Objects;
 import java.util.Optional;
 
 public class StackWalkerUtil {
@@ -12,11 +13,18 @@ public class StackWalkerUtil {
     public static JavaPlugin getFirstPluginCaller() {
         Optional<JavaPlugin> foundFrame = StackWalker.getInstance(StackWalker.Option.RETAIN_CLASS_REFERENCE)
             .walk(stream -> stream
-                .filter(frame -> frame.getDeclaringClass().getClassLoader() instanceof PluginClassLoader)
                 .map((frame) -> {
-                    PluginClassLoader classLoader = (PluginClassLoader) frame.getDeclaringClass().getClassLoader();
-                    return classLoader.getPlugin();
+                    ClassLoader classLoader =  frame.getDeclaringClass().getClassLoader();
+                    JavaPlugin plugin;
+                    if (classLoader instanceof ConfiguredPluginClassLoader configuredPluginClassLoader) {
+                        plugin = configuredPluginClassLoader.getPlugin();
+                    } else {
+                        plugin = null;
+                    }
+
+                    return plugin;
                 })
+                .filter(Objects::nonNull)
                 .findFirst());
 
         return foundFrame.orElse(null);

paper-server/src/main/java/org/bukkit/craftbukkit/CraftServer.java

@@ -280,7 +280,8 @@ public final class CraftServer implements Server {
     private final CraftCommandMap commandMap = new CraftCommandMap(this);
     private final SimpleHelpMap helpMap = new SimpleHelpMap(this);
     private final StandardMessenger messenger = new StandardMessenger();
-    private final SimplePluginManager pluginManager = new SimplePluginManager(this, this.commandMap);
+    private final SimplePluginManager pluginManager = new SimplePluginManager(this, commandMap);
+    public final io.papermc.paper.plugin.manager.PaperPluginManagerImpl paperPluginManager = new io.papermc.paper.plugin.manager.PaperPluginManagerImpl(this, this.commandMap, pluginManager); {this.pluginManager.paperPluginManager = this.paperPluginManager;} // Paper
     private final StructureManager structureManager;
     protected final DedicatedServer console;
     protected final DedicatedPlayerList playerList;
@@ -458,24 +459,7 @@ public final class CraftServer implements Server {
     }
 
     public void loadPlugins() {
-        this.pluginManager.registerInterface(JavaPluginLoader.class);
-
-        File pluginFolder = (File) this.console.options.valueOf("plugins");
-
-        if (pluginFolder.exists()) {
-            Plugin[] plugins = this.pluginManager.loadPlugins(pluginFolder);
-            for (Plugin plugin : plugins) {
-                try {
-                    String message = String.format("Loading %s", plugin.getDescription().getFullName());
-                    plugin.getLogger().info(message);
-                    plugin.onLoad();
-                } catch (Throwable ex) {
-                    Logger.getLogger(CraftServer.class.getName()).log(Level.SEVERE, ex.getMessage() + " initializing " + plugin.getDescription().getFullName() + " (Is it up to date?)", ex);
-                }
-            }
-        } else {
-            pluginFolder.mkdir();
-        }
+        io.papermc.paper.plugin.entrypoint.LaunchEntryPointHandler.INSTANCE.enter(io.papermc.paper.plugin.entrypoint.Entrypoint.PLUGIN); // Paper - replace implementation
     }
 
     public void enablePlugins(PluginLoadOrder type) {
@@ -564,15 +548,17 @@ public final class CraftServer implements Server {
     private void enablePlugin(Plugin plugin) {
         try {
             List<Permission> perms = plugin.getDescription().getPermissions();
-
+            List<Permission> permsToLoad = new ArrayList<>(); // Paper
             for (Permission perm : perms) {
-                try {
-                    this.pluginManager.addPermission(perm, false);
-                } catch (IllegalArgumentException ex) {
-                    this.getLogger().log(Level.WARNING, "Plugin " + plugin.getDescription().getFullName() + " tried to register permission '" + perm.getName() + "' but it's already registered", ex);
+                // Paper start
+                if (this.paperPluginManager.getPermission(perm.getName()) == null) {
+                    permsToLoad.add(perm);
+                } else {
+                    this.getLogger().log(Level.WARNING, "Plugin " + plugin.getDescription().getFullName() + " tried to register permission '" + perm.getName() + "' but it's already registered");
+                // Paper end
                 }
             }
-            this.pluginManager.dirtyPermissibles();
+            this.paperPluginManager.addPermissions(permsToLoad); // Paper
 
             this.pluginManager.enablePlugin(plugin);
         } catch (Throwable ex) {
@@ -1015,6 +1001,7 @@ public final class CraftServer implements Server {
                 "This plugin is not properly shutting down its async tasks when it is being reloaded.  This may cause conflicts with the newly loaded version of the plugin"
             ));
         }
+        io.papermc.paper.plugin.PluginInitializerManager.reload(this.console); // Paper
         this.loadPlugins();
         this.enablePlugins(PluginLoadOrder.STARTUP);
         this.enablePlugins(PluginLoadOrder.POSTWORLD);

paper-server/src/main/java/org/bukkit/craftbukkit/util/CraftMagicNumbers.java

@@ -402,6 +402,16 @@ public final class CraftMagicNumbers implements UnsafeValues {
         net.minecraft.world.item.ItemStack nmsItemStack = CraftItemStack.asNMSCopy(itemStack);
         return nmsItemStack.getItem().getDescriptionId();
     }
+    // Paper start
+    @Override
+    public boolean isSupportedApiVersion(String apiVersion) {
+        if (apiVersion == null) return false;
+        final ApiVersion toCheck = ApiVersion.getOrCreateVersion(apiVersion);
+        final ApiVersion minimumVersion = MinecraftServer.getServer().server.minimumAPI;
+
+        return !toCheck.isNewerThan(ApiVersion.CURRENT) && !toCheck.isOlderThan(minimumVersion);
+    }
+    // Paper end
 
     @Override
     public String getTranslationKey(final Attribute attribute) {

paper-server/src/main/resources/META-INF/services/io.papermc.paper.plugin.entrypoint.classloader.ClassloaderBytecodeModifier

@@ -0,0 +1 @@
+io.papermc.paper.plugin.entrypoint.classloader.PaperClassloaderBytecodeModifier

paper-server/src/main/resources/META-INF/services/io.papermc.paper.plugin.provider.classloader.PaperClassLoaderStorage

@@ -0,0 +1 @@
+io.papermc.paper.plugin.entrypoint.classloader.group.PaperPluginClassLoaderStorage

paper-server/src/main/resources/META-INF/services/org.bukkit.plugin.PluginLoader

@@ -0,0 +1 @@
+io.papermc.paper.plugin.manager.DummyBukkitPluginLoader

paper-server/src/test/java/io/papermc/paper/plugin/PaperTestPlugin.java

@@ -0,0 +1,146 @@
+package io.papermc.paper.plugin;
+
+import io.papermc.paper.plugin.configuration.PluginMeta;
+import org.bukkit.Server;
+import org.bukkit.command.Command;
+import org.bukkit.command.CommandSender;
+import org.bukkit.configuration.file.FileConfiguration;
+import org.bukkit.generator.BiomeProvider;
+import org.bukkit.generator.ChunkGenerator;
+import org.bukkit.plugin.PluginBase;
+import org.bukkit.plugin.PluginDescriptionFile;
+import org.bukkit.plugin.PluginLoader;
+import org.bukkit.plugin.PluginLogger;
+
+import java.io.File;
+import java.io.InputStream;
+import java.util.List;
+
+public class PaperTestPlugin extends PluginBase {
+    private final String pluginName;
+    private boolean enabled = true;
+    private final PluginMeta configuration;
+
+    public PaperTestPlugin(String pluginName) {
+        this.pluginName = pluginName;
+        this.configuration = new TestPluginMeta(pluginName);
+    }
+
+    public PaperTestPlugin(PluginMeta configuration) {
+        this.configuration = configuration;
+        this.pluginName = configuration.getName();
+    }
+
+    @Override
+    public File getDataFolder() {
+        throw new UnsupportedOperationException("Not supported.");
+    }
+
+    @Override
+    public PluginDescriptionFile getDescription() {
+        throw new UnsupportedOperationException("Not supported.");
+    }
+
+    @Override
+    public PluginMeta getPluginMeta() {
+        return this.configuration;
+    }
+
+    @Override
+    public FileConfiguration getConfig() {
+        throw new UnsupportedOperationException("Not supported.");
+    }
+
+    @Override
+    public InputStream getResource(String filename) {
+        throw new UnsupportedOperationException("Not supported.");
+    }
+
+    @Override
+    public void saveConfig() {
+        throw new UnsupportedOperationException("Not supported.");
+    }
+
+    @Override
+    public void saveDefaultConfig() {
+        throw new UnsupportedOperationException("Not supported.");
+    }
+
+    @Override
+    public void saveResource(String resourcePath, boolean replace) {
+        throw new UnsupportedOperationException("Not supported.");
+    }
+
+    @Override
+    public void reloadConfig() {
+        throw new UnsupportedOperationException("Not supported.");
+    }
+
+    @Override
+    public PluginLogger getLogger() {
+        throw new UnsupportedOperationException("Not supported.");
+    }
+
+    @Override
+    public PluginLoader getPluginLoader() {
+        throw new UnsupportedOperationException("Not supported.");
+    }
+
+    @Override
+    public Server getServer() {
+        throw new UnsupportedOperationException("Not supported.");
+    }
+
+    @Override
+    public boolean isEnabled() {
+        return enabled;
+    }
+
+    public void setEnabled(boolean enabled) {
+        this.enabled = enabled;
+    }
+
+    @Override
+    public void onDisable() {
+        throw new UnsupportedOperationException("Not supported.");
+    }
+
+    @Override
+    public void onLoad() {
+    }
+
+    @Override
+    public void onEnable() {
+        throw new UnsupportedOperationException("Not supported.");
+    }
+
+    @Override
+    public boolean isNaggable() {
+        throw new UnsupportedOperationException("Not supported.");
+    }
+
+    @Override
+    public void setNaggable(boolean canNag) {
+        throw new UnsupportedOperationException("Not supported.");
+    }
+
+    @Override
+    public ChunkGenerator getDefaultWorldGenerator(String worldName, String id) {
+        throw new UnsupportedOperationException("Not supported.");
+    }
+
+    @Override
+    public BiomeProvider getDefaultBiomeProvider(String worldName, String id) {
+        throw new UnsupportedOperationException("Not supported.");
+    }
+
+    @Override
+    public boolean onCommand(CommandSender sender, Command command, String label, String[] args) {
+        throw new UnsupportedOperationException("Not supported.");
+    }
+
+    @Override
+    public List<String> onTabComplete(CommandSender sender, Command command, String alias, String[] args) {
+        throw new UnsupportedOperationException("Not supported.");
+    }
+}

paper-server/src/test/java/io/papermc/paper/plugin/PluginDependencyValidationTest.java

@@ -0,0 +1,62 @@
+package io.papermc.paper.plugin;
+
+import io.papermc.paper.plugin.entrypoint.dependency.MetaDependencyTree;
+import io.papermc.paper.plugin.entrypoint.dependency.SimpleMetaDependencyTree;
+import org.bukkit.support.environment.Normal;
+import org.junit.jupiter.api.Test;
+
+import java.util.List;
+
+import static org.hamcrest.MatcherAssert.assertThat;
+
+@Normal
+public class PluginDependencyValidationTest {
+
+    private static final TestPluginMeta MAIN;
+    private static final TestPluginMeta HARD_DEPENDENCY_1;
+    private static final TestPluginMeta SOFT_DEPENDENCY_1;
+
+    public static final String ROOT_NAME = "main";
+
+    public static final String REGISTERED_HARD_DEPEND = "hard1";
+    public static final String REGISTERED_SOFT_DEPEND = "soft1";
+    public static final String UNREGISTERED_HARD_DEPEND = "hard2";
+    public static final String UNREGISTERED_SOFT_DEPEND = "soft2";
+
+    static {
+        MAIN = new TestPluginMeta(ROOT_NAME);
+        MAIN.setSoftDependencies(List.of(REGISTERED_SOFT_DEPEND, UNREGISTERED_SOFT_DEPEND));
+        MAIN.setHardDependencies(List.of(REGISTERED_HARD_DEPEND, UNREGISTERED_HARD_DEPEND));
+
+        HARD_DEPENDENCY_1 = new TestPluginMeta(REGISTERED_HARD_DEPEND);
+        SOFT_DEPENDENCY_1 = new TestPluginMeta(REGISTERED_SOFT_DEPEND);
+    }
+
+    @Test
+    public void testDependencyTree() {
+        MetaDependencyTree tree = new SimpleMetaDependencyTree();
+        tree.add(MAIN);
+        tree.add(HARD_DEPENDENCY_1);
+        tree.add(SOFT_DEPENDENCY_1);
+
+        // Test simple transitive dependencies
+        assertThat("%s was not a transitive dependency of %s".formatted(ROOT_NAME, REGISTERED_SOFT_DEPEND), tree.isTransitiveDependency(MAIN, SOFT_DEPENDENCY_1));
+        assertThat("%s was not a transitive dependency of %s".formatted(ROOT_NAME, REGISTERED_HARD_DEPEND), tree.isTransitiveDependency(MAIN, HARD_DEPENDENCY_1));
+
+        assertThat("%s was a transitive dependency of %s".formatted(REGISTERED_SOFT_DEPEND, ROOT_NAME), !tree.isTransitiveDependency(SOFT_DEPENDENCY_1, MAIN));
+        assertThat("%s was a transitive dependency of %s".formatted(REGISTERED_HARD_DEPEND, ROOT_NAME), !tree.isTransitiveDependency(HARD_DEPENDENCY_1, MAIN));
+
+        // Test to ensure that registered dependencies exist
+        assertThat("tree did not contain dependency %s".formatted(ROOT_NAME), tree.hasDependency(ROOT_NAME));
+        assertThat("tree did not contain dependency %s".formatted(REGISTERED_HARD_DEPEND), tree.hasDependency(REGISTERED_HARD_DEPEND));
+        assertThat("tree did not contain dependency %s".formatted(REGISTERED_SOFT_DEPEND), tree.hasDependency(REGISTERED_SOFT_DEPEND));
+
+        // Test to ensure unregistered dependencies don't exist
+        assertThat("tree contained dependency %s".formatted(UNREGISTERED_HARD_DEPEND), !tree.hasDependency(UNREGISTERED_HARD_DEPEND));
+        assertThat("tree contained dependency %s".formatted(UNREGISTERED_SOFT_DEPEND), !tree.hasDependency(UNREGISTERED_SOFT_DEPEND));
+
+        // Test removal
+        tree.remove(HARD_DEPENDENCY_1);
+        assertThat("tree contained dependency %s".formatted(REGISTERED_HARD_DEPEND), !tree.hasDependency(REGISTERED_HARD_DEPEND));
+    }
+}

paper-server/src/test/java/io/papermc/paper/plugin/PluginLoadOrderTest.java

@@ -0,0 +1,150 @@
+package io.papermc.paper.plugin;
+
+import com.google.common.graph.GraphBuilder;
+import io.papermc.paper.plugin.entrypoint.dependency.SimpleMetaDependencyTree;
+import io.papermc.paper.plugin.provider.entrypoint.DependencyContext;
+import io.papermc.paper.plugin.entrypoint.strategy.modern.ModernPluginLoadingStrategy;
+import io.papermc.paper.plugin.entrypoint.strategy.ProviderConfiguration;
+import io.papermc.paper.plugin.provider.PluginProvider;
+import org.bukkit.support.environment.Normal;
+import org.junit.jupiter.api.Assertions;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.concurrent.atomic.AtomicInteger;
+
+@Normal
+public class PluginLoadOrderTest {
+
+    private static List<PluginProvider<PaperTestPlugin>> REGISTERED_PROVIDERS = new ArrayList<>();
+    private static Map<String, Integer> LOAD_ORDER = new HashMap<>();
+    private static final String[] EMPTY = {};
+
+    static {
+        setup();
+    }
+
+    private static TestJavaPluginProvider setup(String identifier, String[] loadAfter, String[] loadAfterSoft, String[] before) {
+        TestPluginMeta configuration = new TestPluginMeta(identifier);
+        configuration.setHardDependencies(List.of(loadAfter));
+        configuration.setSoftDependencies(List.of(loadAfterSoft));
+        configuration.setLoadBefore(List.of(before));
+
+        TestJavaPluginProvider provider = new TestJavaPluginProvider(configuration);
+        REGISTERED_PROVIDERS.add(provider);
+        return provider;
+    }
+
+    /**
+     * Obfuscated plugin names, this uses a real dependency tree...
+     */
+    private static void setup() {
+        setup("RedAir", EMPTY, new String[]{"NightShovel", "EmeraldFire"}, new String[]{"GreenShovel", "IronSpork", "BrightBlueShovel", "WireDoor"});
+        setup("BigGrass", EMPTY, new String[]{"IronEarth", "RedAir"}, new String[]{"BlueFire"});
+        setup("BlueFire", EMPTY, EMPTY, EMPTY);
+        setup("BigPaper", EMPTY, new String[]{"BlueFire"}, EMPTY);
+        setup("EmeraldSpork", EMPTY, EMPTY, new String[]{"GoldPaper", "YellowSnow"});
+        setup("GreenShovel", EMPTY, EMPTY, EMPTY);
+        setup("BrightBlueGrass", new String[]{"BigPaper"}, new String[]{"DarkSpork"}, EMPTY);
+        setup("GoldPaper", EMPTY, new String[]{"BlueFire"}, EMPTY);
+        setup("GreenGlass", EMPTY, EMPTY, EMPTY);
+        setup("GoldNeptune", EMPTY, new String[]{"GreenShovel", "GoldNeptuneVersioning"}, EMPTY);
+        setup("RedPaper", EMPTY, new String[]{"GoldPaper", "GoldFire", "EmeraldGrass", "BlueFire", "CopperSpork", "YellowDoor", "OrangeClam", "BlueSponge", "GoldNeptune", "BrightBlueGrass", "DarkSpoon", "BigShovel", "GreenGlass", "IronGlass"}, new String[]{"IronPaper", "YellowFire"});
+        setup("YellowGrass", EMPTY, new String[]{"RedAir"}, EMPTY);
+        setup("WireFire", EMPTY, new String[]{"RedPaper", "WireGrass", "YellowSpork", "NightAir"}, EMPTY);
+        setup("OrangeNeptune", EMPTY, EMPTY, EMPTY);
+        setup("BigSpoon", new String[]{"YellowGrass", "GreenShovel"}, new String[]{"RedAir", "GoldNeptune", "BrightBlueGrass", "LightDoor", "LightSpork", "LightEarth", "NightDoor", "OrangeSpoon", "GoldSponge", "GoldDoor", "DarkPaper", "RedPaper", "GreenGlass", "IronGlass", "NightGlass", "BigGrass", "BlueFire", "YellowSpoon", "DiamondGrass", "DiamondShovel", "DarkSnow", "EmeraldGlass", "EmeraldSpoon", "LightFire", "WireGrass", "RedEarth", "WireFire"}, EMPTY);
+        setup("CopperSnow", EMPTY, new String[]{"RedSnow", "OrangeFire", "WireAir", "GreenGlass", "NightSpork", "EmeraldPaper"}, new String[]{"BlueGrass"});
+        setup("BrightBluePaper", EMPTY, new String[]{"GoldEarth", "BrightBlueSpoon", "CopperGlass", "LightSporkChat", "DarkAir", "LightEarth", "DiamondDoor", "YellowShovel", "BlueAir", "DarkShovel", "GoldPaper", "BlueFire", "GreenGlass", "YellowSpork", "BigGrass", "OrangePaper", "DarkPaper"}, new String[]{"WireShovel"});
+        setup("LightSponge", EMPTY, EMPTY, EMPTY);
+        setup("OrangeShovel", EMPTY, EMPTY, EMPTY);
+        setup("GoldGrass", EMPTY, new String[]{"GreenGlass", "BlueFire"}, EMPTY);
+        setup("IronSponge", EMPTY, new String[]{"DiamondEarth"}, EMPTY);
+        setup("EmeraldSnow", EMPTY, EMPTY, EMPTY);
+        setup("BlueSpoon", new String[]{"BigGrass"}, new String[]{"GreenGlass", "GoldPaper", "GreenShovel", "YellowClam"}, EMPTY);
+        setup("BigSpork", EMPTY, new String[]{"BigPaper"}, EMPTY);
+        setup("BluePaper", EMPTY, new String[]{"BigClam", "RedSpoon", "GreenFire", "WireSnow", "OrangeSnow", "BlueFire", "BrightBlueGrass", "YellowSpork", "GreenGlass"}, EMPTY);
+        setup("OrangeSpork", EMPTY, EMPTY, EMPTY);
+        setup("DiamondNeptune", EMPTY, new String[]{"GreenGlass", "GreenShovel", "YellowNeptune"}, EMPTY);
+        setup("BigFire", EMPTY, new String[]{"BlueFire", "BrightBlueDoor", "GreenGlass"}, EMPTY);
+        setup("NightNeptune", EMPTY, new String[]{"BlueFire", "DarkGlass", "GoldPaper", "YellowNeptune", "BlueShovel"}, EMPTY);
+        setup("YellowEarth", new String[]{"RedAir"}, EMPTY, EMPTY);
+        setup("DiamondClam", EMPTY, EMPTY, EMPTY);
+        setup("CopperAir", EMPTY, new String[]{"BigPaper"}, EMPTY);
+        setup("NightSpoon", new String[]{"OrangeNeptune"}, new String[]{"BlueFire", "GreenGlass", "RedSpork", "GoldPaper", "BigShovel", "YellowSponge", "EmeraldSpork"}, EMPTY);
+        setup("GreenClam", EMPTY, new String[]{"GreenShovel", "BrightBlueEarth", "BigSpoon", "RedPaper", "BlueFire", "GreenGlass", "WireFire", "GreenSnow"}, EMPTY);
+        setup("YellowPaper", EMPTY, EMPTY, EMPTY);
+        setup("WireGlass", new String[]{"YellowGrass"}, new String[]{"YellowGlass", "BigSpoon", "CopperSnow", "GreenGlass", "BlueEarth"}, EMPTY);
+        setup("BlueSpork", EMPTY, new String[]{"BrightBlueGrass"}, EMPTY);
+        setup("CopperShovel", EMPTY, new String[]{"GreenGlass"}, EMPTY);
+        setup("RedClam", EMPTY, EMPTY, EMPTY);
+        setup("EmeraldClam", EMPTY, new String[]{"BlueFire"}, EMPTY);
+        setup("DarkClam", EMPTY, new String[]{"GoldAir", "LightGlass"}, EMPTY);
+        setup("WireSpoon", EMPTY, new String[]{"GoldPaper", "LightSnow"}, EMPTY);
+        setup("CopperNeptune", EMPTY, new String[]{"GreenGlass", "BigGrass"}, EMPTY);
+        setup("RedNeptune", EMPTY, EMPTY, EMPTY);
+        setup("GreenAir", EMPTY, EMPTY, EMPTY);
+        setup("RedFire", new String[]{"BrightBlueGrass", "BigPaper"}, new String[]{"BlueFire", "GreenGlass", "BigGrass"}, EMPTY);
+    }
+
+    @BeforeEach
+    public void loadProviders() {
+        AtomicInteger currentLoad = new AtomicInteger();
+        ModernPluginLoadingStrategy<PaperTestPlugin> modernPluginLoadingStrategy = new ModernPluginLoadingStrategy<>(new ProviderConfiguration<>() {
+            @Override
+            public void applyContext(PluginProvider<PaperTestPlugin> provider, DependencyContext dependencyContext) {
+            }
+
+            @Override
+            public boolean load(PluginProvider<PaperTestPlugin> provider, PaperTestPlugin provided) {
+                LOAD_ORDER.put(provider.getMeta().getName(), currentLoad.getAndIncrement());
+                return false;
+            }
+
+        });
+
+        modernPluginLoadingStrategy.loadProviders(REGISTERED_PROVIDERS, new SimpleMetaDependencyTree(GraphBuilder.directed().build()));
+    }
+
+    @Test
+    public void testDependencies() {
+        for (PluginProvider<PaperTestPlugin> provider : REGISTERED_PROVIDERS) {
+            TestPluginMeta pluginMeta = (TestPluginMeta) provider.getMeta();
+            String identifier = pluginMeta.getName();
+            Assertions.assertTrue(LOAD_ORDER.containsKey(identifier), "Provider wasn't loaded! (%s)".formatted(identifier));
+
+            int index = LOAD_ORDER.get(identifier);
+
+            // Hard dependencies should be loaded BEFORE
+            for (String hardDependency : pluginMeta.getPluginDependencies()) {
+                Assertions.assertTrue(LOAD_ORDER.containsKey(hardDependency), "Plugin (%s) is missing hard dependency (%s)".formatted(identifier, hardDependency));
+
+                int dependencyIndex = LOAD_ORDER.get(hardDependency);
+                Assertions.assertTrue(index > dependencyIndex, "Plugin (%s) was not loaded BEFORE soft dependency. (%s)".formatted(identifier, hardDependency));
+            }
+
+            for (String softDependency : pluginMeta.getPluginSoftDependencies()) {
+                if (!LOAD_ORDER.containsKey(softDependency)) {
+                    continue;
+                }
+
+                int dependencyIndex = LOAD_ORDER.get(softDependency);
+
+                Assertions.assertTrue(index > dependencyIndex, "Plugin (%s) was not loaded BEFORE soft dependency. (%s)".formatted(identifier, softDependency));
+            }
+
+            for (String loadBefore : pluginMeta.getLoadBeforePlugins()) {
+                if (!LOAD_ORDER.containsKey(loadBefore)) {
+                    continue;
+                }
+
+                int dependencyIndex = LOAD_ORDER.get(loadBefore);
+                Assertions.assertTrue(index < dependencyIndex, "Plugin (%s) was NOT loaded BEFORE loadbefore dependency. (%s)".formatted(identifier, loadBefore));
+            }
+        }
+    }
+}

paper-server/src/test/java/io/papermc/paper/plugin/PluginManagerTest.java

@@ -0,0 +1,78 @@
+package io.papermc.paper.plugin;
+
+import org.bukkit.Bukkit;
+import org.bukkit.event.Event;
+import org.bukkit.permissions.Permission;
+import org.bukkit.plugin.PluginManager;
+import org.bukkit.support.environment.Normal;
+import org.junit.jupiter.api.AfterEach;
+import org.junit.jupiter.api.Test;
+
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.hamcrest.Matchers.empty;
+import static org.hamcrest.Matchers.is;
+import static org.hamcrest.Matchers.nullValue;
+
+@Normal
+public class PluginManagerTest {
+
+    private static final PluginManager pm = Bukkit.getPluginManager();
+
+    @Test
+    public void testSyncSameThread() {
+        final Event event = new TestEvent(false);
+        pm.callEvent(event);
+    }
+
+    @Test
+    public void testRemovePermissionByNameLower() {
+        this.testRemovePermissionByName("lower");
+    }
+
+    @Test
+    public void testRemovePermissionByNameUpper() {
+        this.testRemovePermissionByName("UPPER");
+    }
+
+    @Test
+    public void testRemovePermissionByNameCamel() {
+        this.testRemovePermissionByName("CaMeL");
+    }
+
+    @Test
+    public void testRemovePermissionByPermissionLower() {
+        this.testRemovePermissionByPermission("lower");
+    }
+
+    @Test
+    public void testRemovePermissionByPermissionUpper() {
+        this.testRemovePermissionByPermission("UPPER");
+    }
+
+    @Test
+    public void testRemovePermissionByPermissionCamel() {
+        this.testRemovePermissionByPermission("CaMeL");
+    }
+
+    private void testRemovePermissionByName(final String name) {
+        final Permission perm = new Permission(name);
+        pm.addPermission(perm);
+        assertThat("Permission \"" + name + "\" was not added", pm.getPermission(name), is(perm));
+        pm.removePermission(name);
+        assertThat("Permission \"" + name + "\" was not removed", pm.getPermission(name), is(nullValue()));
+    }
+
+    private void testRemovePermissionByPermission(final String name) {
+        final Permission perm = new Permission(name);
+        pm.addPermission(perm);
+        assertThat("Permission \"" + name + "\" was not added", pm.getPermission(name), is(perm));
+        pm.removePermission(perm);
+        assertThat("Permission \"" + name + "\" was not removed", pm.getPermission(name), is(nullValue()));
+    }
+
+    @AfterEach
+    public void tearDown() {
+        pm.clearPlugins();
+        assertThat(pm.getPermissions(), is(empty()));
+    }
+}

paper-server/src/test/java/io/papermc/paper/plugin/PluginNamingTest.java

@@ -0,0 +1,30 @@
+package io.papermc.paper.plugin;
+
+import io.papermc.paper.plugin.provider.configuration.PaperPluginMeta;
+import org.bukkit.support.environment.Normal;
+import org.junit.jupiter.api.Assertions;
+import org.junit.jupiter.api.Test;
+
+@Normal
+public class PluginNamingTest {
+    private static final String TEST_NAME = "Test_Plugin";
+    private static final String TEST_VERSION = "1.0";
+
+    private final PaperPluginMeta pluginMeta;
+
+    public PluginNamingTest() {
+        this.pluginMeta = new PaperPluginMeta();
+        this.pluginMeta.setName(TEST_NAME);
+        this.pluginMeta.setVersion(TEST_VERSION);
+    }
+
+    @Test
+    public void testName() {
+        Assertions.assertEquals(TEST_NAME, this.pluginMeta.getName());
+    }
+
+    @Test
+    public void testDisplayName() {
+        Assertions.assertEquals(TEST_NAME + " v" + TEST_VERSION, this.pluginMeta.getDisplayName());
+    }
+}

paper-server/src/test/java/io/papermc/paper/plugin/SyntheticEventTest.java

@@ -0,0 +1,44 @@
+package io.papermc.paper.plugin;
+
+import io.papermc.paper.plugin.manager.PaperPluginManagerImpl;
+import org.bukkit.Bukkit;
+import org.bukkit.event.Event;
+import org.bukkit.event.EventHandler;
+import org.bukkit.event.Listener;
+import org.bukkit.support.environment.Normal;
+import org.junit.jupiter.api.Assertions;
+import org.junit.jupiter.api.Test;
+
+@Normal
+public class SyntheticEventTest {
+
+    @Test
+    public void test() {
+        PaperTestPlugin paperTestPlugin = new PaperTestPlugin("synthetictest");
+        PaperPluginManagerImpl paperPluginManager = new PaperPluginManagerImpl(Bukkit.getServer(), null, null);
+
+        TestEvent event = new TestEvent(false);
+        Impl impl = new Impl();
+
+        paperPluginManager.registerEvents(impl, paperTestPlugin);
+        paperPluginManager.callEvent(event);
+
+        Assertions.assertEquals(1, impl.callCount);
+    }
+
+    public abstract static class Base<E extends Event> implements Listener {
+        int callCount = 0;
+
+        public void accept(E evt) {
+            callCount++;
+        }
+    }
+
+    public static class Impl extends Base<TestEvent> {
+        @Override
+        @EventHandler
+        public void accept(TestEvent evt) {
+            super.accept(evt);
+        }
+    }
+}

paper-server/src/test/java/io/papermc/paper/plugin/TestEvent.java

@@ -0,0 +1,22 @@
+package io.papermc.paper.plugin;
+
+
+import org.bukkit.event.Event;
+import org.bukkit.event.HandlerList;
+
+public class TestEvent extends Event {
+    private static final HandlerList handlers = new HandlerList();
+
+    public TestEvent(boolean async) {
+        super(async);
+    }
+
+    @Override
+    public HandlerList getHandlers() {
+        return handlers;
+    }
+
+    public static HandlerList getHandlerList() {
+        return handlers;
+    }
+}