Originally Posted by JavaCowboy
Looks like Firefox isn't supported because it's an open source project that can't pay royalties on the patent-encumbered H.264 codec.
Not true at all! The beauty of HTML 5 is that it is the responsibility of the user agent (browser) to decide how to handle the file. So in theory at least, if the browser lacks the capability of handling the file in question, it should be able to pass it off to a helper application that can deal with it. That's what Safari does: HTML 5 VIDEO elements are handed off to QuickTime, so if the file is ANY format that QuickTime can handle, it plays. I don't see why a browser couldn't hand off to any media handler that can handle the specified file..heck, you could set the browser up so that "video/MP4" type files get handed off to Flash Player if you want. The point is, instead of the web site telling you how to handle the file, they just give you the data and tell your browser what it is supposed to look like...it's up to your system to render it using any method available.
That Mozilla chooses not to call the system native video handler, preferring instead to limit itself to Ogg Theora, is not a limitation of HTML-5, but a limitation of Mozilla.