In case you haven’t heard of RIAForge.org I urge you to take a look. This project is maintained by Raymon Camdem and you will find open source projects built on top of Adobe technologies. Among the usual suspects, like AIR projects (about 95 for now), Flex (153 projects), or Flash (94 projects) you’ll find projects that build upon ColdFusion, Flash Builder, Dreamweaver, Photoshop just to name a few.
The second project I wanted to tell you about is a continuous integration system for Flex and ActionScript projects that uses Jerkins (formerly known as Hudson). This project was launched by the Slovakia Adobe User Group and it is maintained by Michal Gron. Bravo guys!
If you have open source ActionScript or Flex projects you can have them added to this service. So far you’ll find there AS3 Signals, AS3Corelib, Flixel, Mate framework, Parsley, PicasaFlash API, PushButton Engine, Robotlegs, and Swiz.
PS. Thanks to Juraj Michálek for pointing out these goodies :)