Extension:YouTube

The YouTube extension allows users to embed YouTube and Google Video movies, Archive.org audio and video, WeGame and Gametrailers video, Tangler forum, and GoGreenTube video.

Originally made by and for Wikia, though Wikia no longer uses this video extension.

Usage
To embed a YouTube video:

foo

where foo is the video ID from the URL. i.e. if the video's URL is http://www.youtube.com/watch?v=VyBSS48E4xI, then the embed code would be  VyBSS48E4xI .

See ShoutWiki's help page on using the YouTube extension for more information, such as using alternate, non-YouTube providers to embed content.

See Wikia's old help page about this extension. It explains further details, such as how to set width and height.