so I'm building an R2-D2 droid replica. Chances are (since you're here) you do too, or are at least interested. Note that this SourceForge project does not help you build an R2-D2. If you want that, please head over to http://astromech.net.
So what is the purpose of this project, then? Well, an Astromech droid is a robot. And a robot (if it's not directly remote-controlled) needs some automation, meaning software. This project is intended as a repository and knowledge base for a special niche of robot software, namely software intended for Astromechs and based on WillowGarage's ROS Robot Operating System. For more info on ROS head over to http://www.ros.org.
So there's some software in this repository. What can you do with it? Can you simply download it, put it on your droid and run it? Well mostly, sadly, no (partially, though, yes :-)). There is a big problem with robot software written by, and for, hobbyists. I believe it's not possible to provide robust robot software in the spirit of ready-made, off-the-shelf, tried and tested modules without providing the robot as well, and putting a considerable investment of time and money into it. So there are no ready-made modules here that you can simply download and run and that's it. Most importantly, there is no warranty or ascertained support for any of the software here!
Read that last statement again. It is especially important for R2-D2 replicas, which are often exhibited at shows, amongst little kids etc. That last statement means: do not, under any circumstances, run software on your droid that has not been thoroughly tested on your droid! Especially not software from this project. You've been warned.
That being said, I think it's well possible to work on software for droid automation, as a community, in the knowledge that the result needs to be adapted to and tested on the specific droid it's running on. That collaboration is the purpose of this project. I'm here to have fun with robots, and I hope so are you!