ChestSort will automatically sort every chest after you have closed it. Every player can enable or disable this feature if desired with the simple command `/chestsort`. By default, sorting is disabled. If a player uses a chest for the first time after logging in, they will be shown a text on how to enable automatic chest sorting. Players need the "chestsort.use" permission to use the plugin.
ChestSort takes an instance of org.bukkit.inventory.Inventory and copies the contents. The resulting array is sorted by rules defined in the config.yml. This takes far less than one millisecond for a whole chest. So there should be no problems even on big servers, where hundreds of players are using chests at the same time.