Hpysics is a physics engine to be written using Data Parallel Haskell during Google Summer of Code 2008.
If you are interested, you can follow the blog: http://physics-dph.blogspot.com/
1 Worthy physics engines
- Box2D -- 2D physics engine, notable for "contact persistence algorithm".
- Chipmunk -- 2D physics engine, inspired by Box2D. Fast and simple, written in C.
- Bullet -- 3D engine, shares many of the same algorithms and concepts with Box2D.
- ODE -- popular 3D engine, written in C++.
-  -- modular 3D engine, written in C++. Inspired by ODE.
2 Modular physics engine architecture
2.1 core simulator
Combines all other components to perform simulation.
Method used to integrate ODE.
Physsim implements Euler and Runge–Kutta (implicit and explicit) methods.
2.3 collision detector
Algorithm which detects whether the two bodies overlap.
See also: PQP