An audio library (and kernel level API) for Linux.

A free (LGPL-ed) and open source, cross platform audio library used for 3D and 2D sound.

FMOD is a programming library and toolkit for the creation and playback of interactive audio. It supports all leading operating systems and game platforms.

A high-quality IT/XM/S3M player library. Versions 0.9+ will have MOD support. An add-on is available for playing OGG files. [Freeware]

A software for applying long FIR filters to multi-channel digital audio, either offline or in realtime.

Sound libraries for the PC-DOS platform.

Provides applications running on Pentium-class PCs under MS Windows 9x/NT/2000 with a MIDI-controlled, low-latency, fully programmable wavetable module implemented entirely in software. [Commercial]

An audio system with network support and provides the ability to use stereo, 3D audio, Doppler effects, music playing (MIDI, HMP, MUS), and CD playing and ejecting/changing. [Open source, BSD License]

DRC generates digital room correction FIR filters to be used within HiFi systems in conjunction with real time convolution engines like BruteFIR. [Aladdin Free Public License (AFPL)]

The control of volume is realized by the u32 library. The library can work in all the MS Windows versions (95, 98, ME, NT, 2000 and XP). [Commercial]