API        Platform  State            Tested      Requirements     
-------------------------------------------------------------------
jack       unix      compiles         not tested  libjack
oss        unix      works            Arch Linux  none (?)
alsa       unix      works            Arch Linux  libalsa
asihpi     unix      implemented      not tested  ???
asio       win&mac   not implemented  ---         ASIO SDK, ASIO Drivers, registration
coreaudio  mac       not supported    ---         ---
dsound     win       implemented      not tested  DirectX SDK
wmme       win       works            wine 1.3.4  none (?)
wasapi     win       probably works   wine 1.3.4  Vista SDK (only for MSVC)
wdmks      win       implemented      not tested  DirectX SDK

jack: http://jackaudio.org/
oss: http://www.opensound.com/oss.html
alsa: http://www.alsa-project.org/
asihpi: http://www.audioscience.com/internet/download/linux_drivers.htm
asio: http://www.steinberg.net/en/company/developer.html
coreaudio: http://developer.apple.com/technologies/mac/audio-and-video.html
dsound: http://en.wikipedia.org/wiki/DirectSound
wmme: http://en.wikipedia.org/wiki/Windows_legacy_audio_components#Multimedia_Extensions_.28MME.29
wasapi: http://msdn.microsoft.com/en-us/library/dd371455(VS.85).aspx
wdmks: http://www.portaudio.com/trac/browser/portaudio/trunk/src/hostapi/wdmks/readme.txt