Processing?
 

http://processing.org/

Anyone know if its possible / how hard it'd be to get this env running on the n900 (Maybe with easy debian?)

Re: Processing?
 

Looks like it's a java app, so you'd need a JVM. I haven't installed one yet but there must be a port available. Anyone?

Re: Processing?
 

The thread is called: JAVA on the N900 is possible!

Don't forget that the generation and running itself is going to be pretty slow. Some work would be needed to support OpenGL ES as a renderer, rather than the SDL/OpenGL interfaces they have by default.