Google Open Source - All of Googles open source projects under a single umbrella
Pure Data - Pd (aka Pure Data) is a real-time graphical programming environment for audio, video, and graphical...
LaunchKit - Open Source - A popular suite of developer tools, now 100% open source.
TouchDesigner - TouchDesigner is a visual development platform that equips you with the tools you need to create stunning realtime projects and rich user experiences.
Open Source @IFTTT - A collection of IFTTT OSS projects.
PraxisLIVE - Hybrid visual environment for live creative coding