Looking over the PortAudio specs it's good for a software processing environment but not a lot of use to eg a game. OpenAL appears to be much the other way round.
The thing that always confused me about OpenAL (www.openal.org) is the following part of the spec: OpenAL Fundamentals OpenAL (henceforth, the "AL") is concerned only with rendering audio into an output buffer, and primarily meant for spatialized audio. There is no support for reading audio input from buffers at this time, and no support for MIDI and other components usually associated with audio hardware. Programmers must relay on other mechanisms to obtain audio (e.g. voice) input or generate music. other potential options, depending on intended use: Simple DirectMedia Layer is a cross-platform multimedia library designed to provide low level access to audio, keyboard, mouse, joystick, 3D hardware via OpenGL, and 2D video framebuffer. http://www.libsdl.org/ MidiShare is a musical operating system for Macintosh (MacOS Classic and MacOSX), Windows 3.1, Windows 95/98, Windows NT/2000/XP, Atari and Linux. Result of many years of research and development undertaken by Computer Music Research Laboratory of Grame, MidiShare provides high level services to the field of computer music and MIDI applications. http://www.grame.fr/MidiShare/ others? cheers, claus