projectM - projectM is an LGPL'ed reimplementation of Milkdrop under OpenGL.
cmd.fm UI - Music visualized and controlled via a command line interface
MilkDrop - 3D audio visualization plugin, compatible with WinAmp plugin API
Graphic Foundry - High-impact audio reactive music visualizers 💎
Magic Music Visuals - Fully-customizable and highly responsive visuals for live and recorded audio & MIDI.
SYQEL - Bring your music to life