FlightGear Flight Simulator: free open-source multiplatform flight sim
System dynamics program with additional features for economics
Object-oriented equation-based modelling and optimisation software
physics-based multicellular simulator
Simulation for spacecraft attitude control system analysis and design
Automates the building of VANET simulations using SUMO and OMNeT++
CSS package for contin., discrete and combined modelling & simulation
Growth-grammar related Interactive Modelling Platform
PySCeS Constraint Based Modelling
vinylsimtool: simulation of vinyl record playback
Toolkit for agent-based & dynamic microsimulation modelling
A multi-modeling and simulation environment to study complex systems
Multiagent simulator of road traffic in Qt/C++ and OpenStreetMap.
Acoustic Simulation Library for Frequency and Time Domain Simulations.
An Agent-Based Simulation of Invasive Pest Insects
Managing Ongoing RElationships for Agent-Based Modelling
The Repast Suite is a family of free agent-based modeling libraries.
Simple API for JADE-based Simulations