Ramsophone - A generative art/music machine. (Be sure to refresh!)
Roland 808303.studio - TR-808 drum machine and TB-303 bass synthesizer emulator
Generative Art in Go - Learn the basics of algorithmic art with the Go language
Sampulator - Make (and record) beats on your keyboard
Big Art - Discover street art
Audulus - A universe of sound at your fingertips - Audulus is a modular music processing app