Cisco Packet Tracer - Download Cisco Packet Tracer, an innovative network simulation and visualization tool used by Cisco Networking Academy students and instructors.

Paessler Multi Server Simulator - Paessler Multi Server Simulator is inexpensive and robust software that helps you power massive-scale testing.

GNS3 - GNS3 is a graphical network simulator that allows simulation of complex networks.

ns-3 - a discrete-event network simulator for internet systems

MATLAB - A high-level language and interactive environment for numerical computation, visualization, and programming

FlexSim - Simulation software to model, simulate, predict, and visualize systems in manufacturing, material handling, healthcare, warehousing, mining, etc.