CircuitLogix - CircuitLogix electronics lab simulation provides fast, powerful schematic design and simulation in one complete program.
AnyLogic - AnyLogic has changed simulation modeling and expanded its application into complex business environments. The unmatched flexibility of multimethod modeling allows users to capture the complexity of virtually any system, at any level of detail.
EasyEDA - EasyEDA - Web-based EDA suite; runs in browser.
ns-3 - a discrete-event network simulator for internet systems
LTspice - LTspice® is a high performance SPICE simulation software, schematic capture and waveform viewer with enhancements and models for easing the simulation of analog circuits.
NetSim - NetSim software was created to simulate various Cisco systems. Cisco software is known around the world as being one of the best network, routing and switch systems for businesses and private use. Read more about NetSim.