SimulAxion Physics Engine
Leonardo Boselli sent along the following info about the SimulAxion physics engine:
SimulAxion is a GPL
realtime physics engine under development written in Java.
It models rigid body physics with particles linked togheter. Changing the nature of the links between the particles, one can simulate a wide range of physical properties. This engine is designed for game-like applications and fast performances are more important than accuracy, so it uses many acceptable approximations. The stability of the simulation is guaranteed by a simple Verlet integrator. "