OpenSteer

I don't have code to share, but wanted to make a quick note. I've successfully combined the two by using OpenSteer's integrator as an "intentional" integrator. In other words, instead of using the output of opensteer directly to set an agent's physical properties, I use opensteer's output as inputs to the game's physics system. The end result is that opensteer simply "tries harder" to get the underlying physics to behave the way it wants. In order to make this kind of approach work, you need to understand newtonian mechanics fairly well - otherwise opensteer's outputs can easily be too weak or too strong to properly drive the other system.