MathicGB no longer requires TBB. You still need TBB if you want parallel execution. Removing the requirement for TBB is achieved through an implementation of the parts of the TBB interface that MathicGB uses. This implementation does not do anything in paralle, so it was easy to write. So easy, in fact, that now I'm wondering whether it would make sense to make this implementation support OpenMP, in which case Cygwin would still have parallel execution, just not quite as fast.