Google's plan to open-source the VP8 video codec it acquired when it purchased a company called On2 hasn't exactly been a secret, and the company's finally made it official today as part of a new format called WebM. The WebM container is based on Matroska, with VP8 video and Ogg Vorbis audio streams packed inside -- Google says the format is efficient enough to support playback on lower-power devices like netbooks, tablets, and handhelds, while the encoding profiles are simple enough to limit complexity when you're trying to create WebM files. WebM is open-sourced and licensed royalty-free under a BSD-style license, so all those H.264 patent licensing concerns shouldn't be an issue -- and as you'd expect, Mozilla is supporting WebM right off the bat, with support in Firefox nightly builds as of today. Chromium nightlies will also support WebM as of today, with Chrome early access builds getting support on May 24 -- and Opera is listed as "coming soon."