The Xiph.Org Foundation is a non-profit organization dedicated to producing public domainmultimedia formats and tools. Their primary focus is on the Ogg family of formats, the most successful of which has been Ogg Vorbis, an open and patent-free audio format and codec designed to compete with the patented MP3 and AAC. Current development work is focusing on Ogg Theora, an open and patent-free video format and codec designed to compete with the patented MPEG-4, RealVideo, and Windows Media Video.
In addition to its in-house development work, the Foundation has also brought several already-existing but complementary free software projects under its aegis, most of which have a separate, active group of developers. Among these are Speex, an audio codec designed for speech, and FLAC, a lossless audio codec.
Xiph is an open source project, and people are free to contribute what they think is useful under our general umbrella.
I've been more inspired to work on xiph stuff lately, largely because Emmett has left (I'm sorry to say) and (I'm not sorry to say at all) jack is asserting himself again.
Xiph has grown quite a bit lately, accreting several other projects, and it's gotten hard to keep follow everything that's going on or figure out how to contribute.