ALSA Project: www.alsa-project.org [1]
Alternate Sound APIs:
aRts and CSL: www.arts-project.org [2]
JACK: jackit.sourceforge.net [3]
OpenAL: www.openal.org/home [4]
SDL: www.libsdl.org [5]
Sound and MIDI Software for Linux: linux-sound.org [6]
Links:
[1] http://www.alsa-project.org
[2] http://www.arts-project.org
[3] http://jackit.sourceforge.net
[4] http://www.openal.org/home
[5] http://www.libsdl.org
[6] http://linux-sound.org