TheoraDecoders

theora: reference encoder/decoder (the decoder support all theora features) library with MMX optimizations: theora svn, theora official releases.
theora-old: old encoder/decoder (the decoder does not support all theora features, but it's faster than theora in many cases) library, with MMX optimizations; theora version up to 1.0 alpha 7 were using this code trunk: theora-old svn.
theora-exp: experimental encoder/decoder (the decoder is more or less the same of reference, the encoder is new and supports all theora features but it's not really usable) library: theora-exp svn.
theora-exp-mt: experimental decoder (based on an old version of the reference decoder) optimized for SMP/multi core systems: theora-exp-mt svn.
Cortado: a GPL Java decoder for Ogg Theora, Ogg Vorbis and other codecs. Embedding this applet on your website you can give viewers access to streams from either the Flumotion streaming server or play a local file from your server without the need for a locally installed media player supporting the correct formats on the visitors computer.
ffmpeg (only vp3 features, mmx, sse2 optimisations).
Etheora: a simplified API to theora reference encoder/decoder.

See also