OpenNum lets you distribute solvers with a nice graphical interface
A wireless push-type network simulator.
NMR Product Operator Calculator
Modbus slave simulator
Portable OS X FOSS applications
PySCeS Constraint Based Modelling
A software gps simulator
Tool for the evaluation of ALgorithms for Embedding VIrtual Networks
A multi-modeling and simulation environment to study complex systems
Prediction of proteinfolding in 2D HP model
NeuralSyns is a neural simulator for large spiking networks.