SuperCollider
Real-time audio synthesis engine and music programming language
N.B. SuperCollider is now hosted at GitHub, and the most recent versions can be downloaded from there. http://supercollider.github.io
A real time audio synthesis engine, and an object-oriented programming language specialised for music.
SuperCollider was created in 1996 by James McCartney, now (since version 3) released as free software.