Speex
The Speex project is an attempt to create a free software speech coder, unencumbered by patent restrictions. Speex is licensed under the BSD License and is part of the Xiph.org foundation (like Vorbis).Although not a formal part of the Ogg multimedia project, the Speex coder uses the Ogg bitstream format, and the Speex designers see their project as complementary to the Vorbis general-purpose audio compression project.
In their FAQ, the Ogg project recommends that applications designers looking for a general-purpose speech coder should consider Speex.
