I managed to play around with this before it went offline, and have to say it is very impressive.
It's a marriage between Google Wave and Processing with a very nice interface.
Would love to see this incorporated into openprocessing.org to be able to quickly add a few tweaks to other peoples sketches. It would be like a github for processing sketches with online editing!
Agreed. CC-BY-SA is the default license for sketches created on both SketchPad and OpenProcessing, which makes modifications and cross-polinations possible. I discuss a few of the possibilities on the sketchpad blog (which is currently in a half-functional state): http://blog.sketchpad.cc/2010/05/default-cc-by-sa/
Keep an eye out for clone/fork functionality (but don't hold your breath for a merge option.)
The home page loaded after waiting for a bit, and it seems to be a merge of Etherpad and Processing. You collaboratively edit Processing code, and it shows up to the right of the pad. I'm excited to try it!
You can take a look at this screencast to get a feel for it. Watching a video is admittedly a poor substitute for trying it out yourself, but it's the best I can offer right now. Sorry.
Would love to see this incorporated into openprocessing.org to be able to quickly add a few tweaks to other peoples sketches. It would be like a github for processing sketches with online editing!