The Freesound Project is a collaborative database of Creative Commons licensed sounds. Freesound focusses only on sound, not songs. This is what sets freesound apart from other splendid libraries like ccMixter. New to this site? Read the What is Freesound page to learn more!
Foobar2000 is an advanced audio player for the Windows platform. Some of the basic features include full unicode support, ReplayGain support and native support for several popular audio formats.
a library for reading and editing the meta-data of several popular audio formats. Currently it supports both ID3v1 and ID3v2 for MP3 files, Ogg Vorbis comments and ID3 tags and Vorbis comments in FLAC files.
FluidSynth is a real-time software synthesizer based on the SoundFont 2 specifications. FluidSynth can read MIDI events from a MIDI input device and render them to an audio device using SoundFont instruments.