Theora

Theora is a video codec for the ogg project, and is currently (as of the end of 2004) in the alpha stage of development. Theora is based on VP3 by the company On2, and for those worried about patents and the like, it was made sure it wouldn't be a problem (you can read more on Theora's web page listed below, go to their FAQ section).

Although it's in alpha, you can encode using this codec through the sample encoder, though the encoder is not installed with Theora - after you compile Theora go into the directory &quot;examples&quot;, there you will find examples of an encoder, decoder, etc... mplayer currently supports Theora if it's installed, as for the actual codec, it currently gives less compression than mpeg4, though seeing how Theora is still in alpha, this video codec looks very promising.