ArcDev Noise Industries makes nonstandard vst plugins for nonstandard musicicians.

Makes SIDPLAY, a Commodore 64 music player for Mac OS X

AudioMulch Interactive Music Studio. Real-time sound synthesis and audio processing software usable as an audio effects processor or a complete music composition and performance system. AudioMulch contains many audio synthesis and processing modules and may also be used to host VST plugins.

Glitch Sequencer is a free cellular automaton based MIDI sequencer for the PC and Mac.

Freeware plug-in and virtual instrument for Mac

TuxGuitar Official Web Site.

Algorithmic VSTI music sytems by H.G. Fortune

Official website of the virtual loopstation Ambiloop

Cochleor offers audio software such as Harmony Improvisator (Harmonic MIDI sequencer) and Visual Vox (pitch correction from polyphonic audio material).

Editor of Net Tunes the ultimate iTunes remote control solution for networked users.