WordPress/wp-includes/default-widgets.php

<?php
/**
 * Widget API: Default core widgets
 *
 * @package WordPress
 * @subpackage Widgets
 * @since 2.8.0
 */

/** WP_Widget_Pages class */
require_once( ABSPATH . WPINC . '/widgets/class-wp-widget-pages.php' );

/** WP_Widget_Links class */
require_once( ABSPATH . WPINC . '/widgets/class-wp-widget-links.php' );

/** WP_Widget_Search class */
require_once( ABSPATH . WPINC . '/widgets/class-wp-widget-search.php' );

/** WP_Widget_Archives class */
require_once( ABSPATH . WPINC . '/widgets/class-wp-widget-archives.php' );

/** WP_Widget_Meta class */
require_once( ABSPATH . WPINC . '/widgets/class-wp-widget-meta.php' );

/** WP_Widget_Calendar class */
require_once( ABSPATH . WPINC . '/widgets/class-wp-widget-calendar.php' );

/** WP_Widget_Text class */
require_once( ABSPATH . WPINC . '/widgets/class-wp-widget-text.php' );

/** WP_Widget_Categories class */
require_once( ABSPATH . WPINC . '/widgets/class-wp-widget-categories.php' );

/** WP_Widget_Recent_Posts class */
require_once( ABSPATH . WPINC . '/widgets/class-wp-widget-recent-posts.php' );

/** WP_Widget_Recent_Comments class */
require_once( ABSPATH . WPINC . '/widgets/class-wp-widget-recent-comments.php' );

/** WP_Widget_RSS class */
require_once( ABSPATH . WPINC . '/widgets/class-wp-widget-rss.php' );

/** WP_Widget_Tag_Cloud class */
require_once( ABSPATH . WPINC . '/widgets/class-wp-widget-tag-cloud.php' );

/** WP_Nav_Menu_Widget class */
require_once( ABSPATH . WPINC . '/widgets/class-wp-nav-menu-widget.php' );