Audacity - Audacity is a free and open-source audio production software suite that includes a surprising array of editing tools and recording systems.
Magic Music Visuals - Fully-customizable and highly responsive visuals for live and recorded audio & MIDI.
Oceanaudio - Ocenaudio is a cross-platform, easy to use, fast and functional audio editor.
MilkDrop - 3D audio visualization plugin, compatible with WinAmp plugin API
GoldWave - GoldWave. Digital Audio Editing Software. Record • Restore • Convert • Analyze. Fully loaded to do everything from the simplest recording and editing to the most sophisticated audio processing, restoration, enhancements, analysis, and conversions.
Kauna - Kauna is a music visualizer. Kauna renders any sound reproduction in system.