There are two main packages in Simbrain: the Simbrain package, which contains all the code for the GUI and its components, and the simnet package which contains the code for the simbrain neural networks. The Simbrain package contains the GUI representation of neural networks, gauges, worlds, couplings, and the workspace. Neural networks, gauges, and worlds are thre three visible components in Simbrain: neural nets are simulated brain circuits, worlds simulate methods of producing inputs to and accepting outputs from neural networks, and gauges represent the states that have occurred in a neural network (either neuron and weight states). Couplings control interactions between neural networks and worlds. Worlds are components which produce inputs to neural networks and accept outputs. The workspace is the GUI space which contains all particular components.