The Plasimo code is a toolbox that provides support for the numerical simulation of plasma sources of various degrees of equilibrium. It comes with a number of electromagnetic modules, flow solvers, modules for calculating transport coefficients, radiation transport and for the generation of ortho-curvilinear coordinate systems. Plasimo supports transient and steady-state simulations of plasma sources in one-, two and three-dimensional geometries. This paper presents a selection of Plasimo's sub-models. A discussion of the physics behind each module is accompanied by notes about the module's capabilities and limitations and by references to original works and papers in which that particular module was used. As such, it provides a good entry point for people who consider using Plasimo—or parts of it—for their simulation needs.