WebM – An Open Media File Format based on Matroska
The big news today is that WebM will join the list of open and freely usable Web formats, and video will finally become a first-class citizen of the Web. The WebM launch is supported by Mozilla, Opera, Google and more than forty other publishers, software and hardware vendors.

WebM defines the file container structure, video and audio formats.
In more detail, it is a video format consisting of:
- VP8, a video codec released today under a BSD-style, royalty-free license (owned by Google from their acquire of On2 Technologies).
- Vorbis, open-source audio codec.
- A container format based on Matroska.
More about WebM:
- Opera supports the WebM video format
- Explore the WebM Source Code
- The WebM Video Format – The Saviour Of Open Video On The Web?
P.S. The web has always been open and freely-usable; Tim didn’t patent HTML, Håkon didn’t patent CSS and Brendan didn’t patent JavaScript.