Vvvv - vvvv is a graphical programming environment for easy prototyping and development.
Bosca Ceoil - A free, easy to use tool for creating music.
Processing - C++ and Java programming at the speed of thought.
Zynewave Podium - Podium is a modern digital audio workstation (DAW) for Windows.
Vuo - Design and build live interactive media.
Renoise - Renoise is a digital audio workstation.