Ask HN: Please suggest me some good open source physics engines

Depending on your exact needs, there's a moderate trend towards using game engines for this sort of thing. Two simulation-oriented projects:

* The Delta3d game/simulation engine is mainly funded by the U.S. military, for simulation and training applications: http://www.delta3d.org/

* The USARSim robot simulator is built on top of the Unreal Tournament game engine: http://usarsim.sourceforge.net/

Delta3d is open source; USARSim itself is open source, but depends on the non-open-source Unreal engine.

Thank you guys.