The Advanced Linux Sound Architecture is composed of several parts. The first is a fully modularized sound driver which supports module autoloading, devfs, isapnp autoconfiguration, and gives complete access to analog audio, digital audio, control, mixer, synthesizer, DSP, MIDI, and timer components of audio hardware. It also includes a fully-featured kernel-level sequencer, a full compatibility layer for OSS/Free applications, an object-oriented C library which covers and enhances the ALSA kernel driver functionality for applications (client/server, plugins, PCM sharing/multiplexing, PCM metering, etc.), an interactive configuration program for the driver, and some simple utilities for basic management.
SDLucid is a C++ wrapper library for the SDL media library. It aims to not only be a wrapper, but to also offer a cleaner interface than the original SDL, as well as increased functionality. This additional functionality includes fonts, PNG loading, graphical primitives, built-in mixing, mod playing, and MP3 decoding. SDLucid follows naming conventions, approximating those of the Standard Template Library.
irrKlang is a high level 2D and 3D cross platform sound engine and audio library that plays WAV, MP3, OGG, MOD, XM, IT, S3M, and other file formats. It can be used by C++ and all .NET languages (C#, Visual Basic.NET, etc.). It has all of the features common to low-level audio libraries as well as lots of useful features like a sophisticated streaming engine, extendable audio reading, single and multi-threading modes, 3D audio emulation for low-end hardware, a plugin system, multiple rolloff models, sound effects, and more. All of these can be accessed via an extremely simple API using an object oriented design.