Mozilla, Google, Opera and forty other publishers such as Adobe have announced WebM, a “project dedicated to developing a high-quality, open video format for the web that is freely available to everyone.” This projects aims at setting the web free with an open alternative to the h2.64 format championed by Apple and Microsoft.
WebM project features VP8, a high-quality video codec now licensed under open BSD after its acquisition by Google, Vorbis a well known open source and broadly implemented audio codec. Together with the open codecs, WebM uses the Matroska media container which supports streaming, subtitles, multiple audio channel etc. Right now Chromium, Opera and Firefox web browsers have experimental builds with WebM available to download.
Free Open Source tools now available for creating and publishing content in the WebM format include FFmpeg Patches, DirectShow Filters, and a new VP8 SDK for building native VP8 decode and encode functionality into your applications. GStreamer Plug-ins are coming soon. Commercial alternatives to the above mentioned tools are also available in the WebM Tools page
Now visit the WebM project for more information. WebM is “royalty-free” (you can do whatever you want with the WebM code without owing money to anybody), more information on License page but the VP8 codec source code and specification are licensed differently.