EsounD, the Enlightened Sound Daemon, is a server process that mixes several audio streams for playback by a single audio device. For example, if you’re listening to music on a CD and you receive a sound-related event from ICQ, the two applications won’t have to jockey for the use of your sound card.

More information is available at http://www.tux.org/~ricdude/EsounD.html but the latest source is available from the Gnome project.

See http://cvs.opendarwin.org/cgi-bin/cvsweb.cgi/projects/NetworkAudioDevice/

This is a kernel extension that creates a virtual audio output device that can be used to stream audio across the network to an EsounD server.

Hasn’t been updated for awhile. Has anyone tested this recently?