WebM from Google →

As expected, Google announced this morning that it is open-sourcing the VP8 video codec acquired during its buyout of On2. The codec will be included in a new video container format called WebM.

WebM includes:

• VP8, a high-quality video codec we are releasing today under a BSD-style, royalty-free license
• Vorbis, an already open source and broadly implemented audio codec
• a container format based on a subset of the Matroska media container

WebM is supported by over 40 companies, including Mozilla, Opera, and Adobe, and Microsoft issued a statement offering limited support in IE9.

This was expected to provide a higher-quality alternative to Theora and Dirac video codecs, while remaining open-source, unlike H.264, currently the most popular web video codec. This would then make it an ideal candidate for the default implementation of the HTML5 video tag. Upon a technical analysis, however, it appears that even with user improvements, VP8 will lag behind H.264 in visual quality and is in fact similar enough to H.264 to allow for possibility of patent infringement claims.

More Information:
Ars Technica
Engadget
TechCrunch