http://www.beet.tv/2009/06/what-the-hell-is-ogg-theora-and-should-we-care-mike-hudack-explains.html
NEW YORK , NY -- There is a powerful movement underway for open video standards for the Web. The biggest implementation will be seen very soon on Wikipedia where you will watch videos in an open source video application called Ogg Theora. The imminent release of Firefox 3.5 will come with HTML 5, which allows video to be embedded into the Web page without the need for plug-in's.
Andy Plesser, Executive Producer