runBioSimulations is a free tool for running a wide range of biological simulations. Through the BioSimulators registry of biosimulation tools, runBioSimulations supports a broad range of modeling frameworks (e.g., logical, kinetic), simulation algorithms (e.g., FBA, SSA), modeling formats (e.g., SBML, SED-ML), and simulation tools (e.g., COBRApy, COPASI).