Projects

JSyn - modular synthesis API for Java.
JMSL - Java Music Specification Language
PortAudio - cross platform audio I/O API for 'C'

Programming Languages, APIs, Libraries

PLUM - Programming Languages Used for Music

Multi-Platform

Java

Macintosh (also see Multi-Platform section)

Linux (also see Multi-Platform section)

Plugins

Windows (also see Multi-Platform section)