Just when it looked like HTML 5 might pave the way for a truly universal web page rendering standard, the most important specifications for the 21st century—audio and video—will languish, perhaps to die on the vine. Ian Hickson:
After an inordinate amount of discussions, both in public and privately, on the situation regarding codecs for video and audio in HTML 5, I have reluctantly come to the conclusion that there is no suitable codec that all vendors are willing to implement and ship.
In other words, major browser publishers, including Apple, Mozilla, Google, Opera, and Microsoft could not agree on which codec to use, so, no standard. The fragmented mess continues.