cSim is a simulator for linear control systems. It enables the simulation of block diagrams made up of transfer functions and/or state equations. The diagram is generated automatically according to the topology chosen by the user. Continuous and discrete time controllers with one or two loops are possible, as well as feedforward and disturbance blocks. To facilitate the editing of transfer functions and state equations, polynomials and matrices respect the MATLAB software format. After simulation, the output of any block can be easily plotted. Although cSim is a simulator for linear control systems, it allows saturation and a dead zone for some specific blocks. For source blocks, the user can choose between step, slope, and sinusoidal functions. Block diagrams can also be saved, loaded, and emailed.