Firefox and Opera are both backed Ogg Theora [1] [2]. WebKit (Safari and, I guess?, Chrome) looks like it has QuickTime formats with more being supported down t

Firefox and Opera are both backed Ogg Theora [1] [2]. WebKit (Safari and, I guess?, Chrome) looks like it has QuickTime formats with more being supported down the road [3]. (These are all pretty old articles I remember from the top of my head. I'd predict that the body of video formats will probably stabilize soon with Theora winning.) [1]: http://www.bluishcoder.co.nz/2007/05/support-for-html-video-element-in.html http://www.bluishcoder.co.nz/2007/05/support-for-html-video-... [2]: http://dev.opera.com/articles/view/a-call-for-video-on-the-web-opera-vid/ http://dev.opera.com/articles/view/a-call-for-video-on-the-w... [3]: http://webkit.org/blog/140/html5-media-support/ http://webkit.org/blog/140/html5-media-support/