Pure Data - Pd (aka Pure Data) is a real-time graphical programming environment for audio, video, and graphical...
Google Open Source - All of Googles open source projects under a single umbrella
TouchDesigner - TouchDesigner is a visual development platform that equips you with the tools you need to create stunning realtime projects and rich user experiences.
SmallDevTools - Handy developer tools with a delightful interface
PraxisLIVE - Hybrid visual environment for live creative coding
whatdevsneed - This is whatdevsneed.