FlightGear Flight Simulator: free open-source multiplatform flight sim
System dynamics program with additional features for economics
The Open Source CFD Toolbox
Object-oriented equation-based modelling and optimisation software
Simulation for spacecraft attitude control system analysis and design
Class library for computational cybernetics
Automates the building of VANET simulations using SUMO and OMNeT++
Growth-grammar related Interactive Modelling Platform
CSS package for contin., discrete and combined modelling & simulation
PySCeS Constraint Based Modelling
Cellular Automata library for SUPercomputers (CASUP)
vinylsimtool: simulation of vinyl record playback
Toolkit for agent-based & dynamic microsimulation modelling
A multi-modeling and simulation environment to study complex systems
The DREAM toolbox is a free open source acoustic field simulation tool
Acoustic Simulation Library for Frequency and Time Domain Simulations.