keezy - A colorful soundboard. Play with music.
Roland 808303.studio - TR-808 drum machine and TB-303 bass synthesizer emulator
Figure - Propellerhead creates world-class software products and services that inspire music makers and provide the foundation for a worldwide creative musical community.
Sampulator - Make (and record) beats on your keyboard
Splice - Music creation, collaboration, and sharing made simple.
Audulus - A universe of sound at your fingertips - Audulus is a modular music processing app