mixmello - mixmello is a free, open source tool to create remixed versions of your favourite playlists.
The Rick Astley Remixer - Remix your favourite songs in your browser.
Incredibox - Express your musicality, pump it up and chill
Remix - Solidity IDE (Integrated Development Environment)
Musicroamer - A visual Pandora for discovering new music
Google Music Lab - Interactive experiments that use the Web Audio API