FlightGear Flight Simulator: free open-source multiplatform flight sim
SUMO is a microscopic, multi-modal traffic simulation.
System dynamics program with additional features for economics
Virtual X-Ray Imaging Library on GPU
Individual-based forward-time genetics simulation software
Open source software calculating industrial noise in the environment
ASALI is an open-source code for chemical engineers
Fast integrator of stochastic partial differential equations
turn-based wargame/simulator
Interactive geometry software for Euclidean and non-Euclidean spaces
HP-41cx Emulator
Molecular Dynamics Cell Construction