FlightGear Flight Simulator: free open-source multiplatform flight sim
Virtual X-Ray Imaging Library on GPU
Object-oriented equation-based modelling and optimisation software
Antimony is a human-readable, human-writable model definition language
PPface is vector processor emulator / simulator
OpenM++: open source microsimulation platform
Fancy interactive fluid simulation for gfx fans, VJs and demo coders
A particle simulation visualization program
Stochastic Analysis
NEVESIM is an event-driven neural simulation tool.
Visu@lGrid - IDE for Building BOINC Projects
LIME is a software tool for creating multiphysics simulation codes.