Uber Cloud - UberCloud is the cloud for engineers that provides cloud simulation solutions for engineers and scientists.
FlexSim - Simulation software to model, simulate, predict, and visualize systems in manufacturing, material handling, healthcare, warehousing, mining, etc.
MapleSim - MapleSim is an advanced system-level modeling tool that enables innovation and reduces development risk.
ns-3 - a discrete-event network simulator for internet systems
PowerFLOW - Learn more about how PowerFLOW CFD solutions utilize complex geometry to perform aerodynamic, aeroacoustic and thermal management simulations.
Paessler Multi Server Simulator - Paessler Multi Server Simulator is inexpensive and robust software that helps you power massive-scale testing.