Pymunk is a easy-to-use pythonic 2d physics library
Creative cellular automata browser game
Library for the numerical simulation of closed as well as open quantum
Cellular Automata library for SUPercomputers (CASUP)
Multithreaded N-Point Gravity Simulation for PC and Android
Advanced numerical instruments: adaptive meshing, FE methods, solvers
Box2d Flash Alchemy Port + World Construction Kit