FLAC is an open-source project which specifies a lossless compressed audio format and provides an encoder, decoder, and several player plugins. Aside from yielding better compression than Shorten, the format supports sample-accurate seeking and many other features useful for streaming and archival.

Reader Colin B. says: Incredible lossless audio compression, depending on the source, of course. I have seen high-quality speech recordings compressed to 10% of the original size, losslessly..

FLAC 1.1.0 released in January, 2003. A good roster of new features for this coder, including updates for libraries and plugins.

http://flac.sourceforge.net/