Singleton that registers and instantiates WP_Widget classes.

Flushes the Recent Comments widget cache.

Retrieves the taxonomy for the current Tag cloud widget instance.

Gets the timestamp of the last time any post was modified or published.

Updates category structure to old pre-2.3 from new taxonomy structure.

Creates an XML string from a given array.

Prepare the oembed HTML to be displayed in an RSS feed.

Hooks into the REST API output to print XML instead of JSON.

Adds any comments from the given IDs to the cache that do not already exist in cache.

Get the image size as array from its meta data.