Havok allows free use of the physics engine for anyone who doesn't charge for the games built on the platform. There are no non-profit OpenSim grids yet that use Havok.
"One of the things that surprised (and pleased) me this year was the (unprompted) willingness of students to source and implement LSL scripts for their OpenSim builds. It definitely added another dimension to their work. That said, I don't teach a programming course per se so it would be good if students had a simple way to generate script not available "off the shelf"."