Wonderland/Darkstar

Another interesting project in this area is Wonderland:
  https://lg3d-wonderland.dev.java.net/
which uses
  http://www.projectdarkstar.com/
as its underlying engine.

A quick summary of darkstar can be found here (the actual project homepage is really hard to
get a good overview from):
  http://research.sun.com/projects/dashboard.php?id=168

This appears to be a pretty serious effort by Sun to build a highly,scalable system with the
same "grid" features discussed above.

Wonderland at least is under the GPL2.0.

I'm pretty sure I read earlier that darkstar is also under an open-source license, but cannot
find a clear link that states that at the moment.