I'm glad that no ones mentioned acid 3 or such tests lately, it's been found that browsers placing an emphasis on acid tests have been implementing minimum functionality in order to score points, but the required functions are useless at their task (other than to score points). Webkit developers have blogged about getting pissed off about this. Mozilla has down-played the importance of the acid tests from the start and played an honest game - the scores come slowly after much slavery ambushing internals to comply fully with the standards (functionally important parts first, score-relevant ones last).
There are too many reasons that I think I correctly regard Mozilla and not a bit of the rest as the 'savior' of the principles of the web - above the fact that Firefox actually saved those principles by becoming one of the most popular pieces of software ever.
Mozilla's stubbornness on H.264 is one of those reasons. H.264 is patented. The MPEG-LA control H.264 licenses to decode and encode (i.e. produce) H.264 videos. It would have costed Firefox in the order of hundreds of millions of dollars to support playback of H.264 videos, but the MPEG-LA actually are offering a gratis license for Firefox specifically, so why don't Mozilla accept that deal? (Other than the fact that it's a time-limited deal! disclaimer, this situation could have changed since I last was reading about this)
It's as clear as day that MPEG-LA are trying to create a monopoly on video (which they've done) and bring it to the web too. This should not be allowed to happen. Firefox will never implement a patented video codec for the same reason they rejected ActiveX support (yes, they had an implementation!). The web is for everyone. It's not for Windows users, and it should not be the way that you need to pay a licensing authority to produce video for it, or to play it back. There is nothing the MPEG-LA can do to make H.264 use acceptable in view of the original principles of the web above making it royalty free, for everybody. Making it faster and better than the competition does not achieve this. H.264 is a fair bit better than WebM because of a number of reasons, but it's all in the name: WebM fits in with the principles of the web, H.264 by MPEG-LA results in a stranglehold, again.
Firefox supports WebM and OGG. IE9 supports whatever the OS supports I THINK. This includes OGG and WebM AND H.264 all out of the box. Chrome does a similar thing to IE9 I think, and it supports all of them out of the box I think. Safari (including iPads, iPhone, iPods) supports H.264, and has no support for OGG or WebM out of the box. This is a major problem, but at least Apple are on their own on this one, without even MS to join them. Make your own mind up about Apple, abusing their control and market share over devices to push for a H.264 web. Thanks to them, developers can't make do with a single video file if they want to support free standards, remind you of anyone?