[game_edu] Open source RTS engine recommendations?

[pawlicki at cs.rochester.edu]

Does anyone have recommendations of open source RTS
development platform?

The CSC department would like to identify an open source RTS engine.
We want to use it as research tool on a multi-year project and
also as a tool to teach in our Artificial Intelligence course.

We could use some help figuring out which platform would be best.

Currently, we are looking at

the Spring engine
http://en.wikipedia.org/wiki/Spring_project
or warzone
http://en.wikipedia.org/wiki/Warzone_2100

but if some of you have knowledge or experience with
other platforms, then we would certainly appreciate the
input.

In general, our requirements are :

 - free: can't require commercial game even for graphic/sound resources
 - cross-platform (linux & mac first, windows is less of a priority)
 - hackability: have to be able to plug in external AI (not necessarily
sockets, but something better than pure hacking)
 - customizability: have to be able to build new environments

Thanks,

Ted Pawlicki, PhD.
Undergraduate Program Director
Department of Computer Science
University of Rochester,
pawlicki at cs.rochester.edu