Qucs-S is a circuit simulation program with Qt-based GUI
FlightGear Flight Simulator: free open-source multiplatform flight sim
Quantum Mechanical Charge Field - Molecular Dynamics
Circuit simulator for power electronics
PCRaster environmental modeling software
Cellular Automata library for SUPercomputers (CASUP)
Parallel simulators for Membrane Computing on the GPU
A highly flexible 3D flocking boids simulator, conceived as a tool for
Weighted Implementation of Suboptimal Paths (WISP)
3D model viewer and world navigator.