The Pure Data (short Pd) project on SourceForge unifies the extensions (or externals) written for the Pure Data Graphical Computer Music System written by Miller Puckette with contributions from many others.
Midimatcher is a tool for analyzing a large collection of musical works by one or more composers. The program identifies musical fragments in the melody line that recur. The program contains a convenient graphical/audio interface
OSW is a graphical programming environment for real-time music and audio applications. Users connect objects called transforms to form programs called patches. OSW currently runs on Windows, Linux, Mac OS X and SGI platforms.