DaVinci Resolve - Revolutionary new tools for editing, color correction and professional audio post production, all in a single application!
Visual Beat - Interactive music video
Kdenlive - Free and open-source, full-featured video editor.
The Lucid Realm - Listen to music in 3D
Mastershot App - Mastershot’s intuitive web-based video editor will have you churning out high quality videos in no time at all. And best of all, it's 100% free!
Google Music Lab - Interactive experiments that use the Web Audio API