The Classic Intelligent Composing and Performing System
M 2.7 is a Mac OS X version of a program first published by Intelligent Music in 1987. In the 1980s, M ran on four different computer platforms (Mac, Windows, Atari, and Amiga), and had many fans all over the world.
M was quite different from any other music software when it first appeared, but many musicians and composers were attracted to its powerful implementation of the idea of interactive composition, where you shape the music as you hear it unfold. M 2.7 features compatibility with OS X Core MIDI so you can use it to power the software synthesizers that sound great but are always need of better material.
via M « Cycling 74.