BioSimulators is a free registry of biosimulation tools. The registry includes tools for a broad range of frameworks (e.g., logical, kinetic), simulation algorithms (e.g., FBA, SSA), and model formats (e.g., BNGL, CellML, NeuroML/LEMS, SBML, Smoldyn). Many of the simulation tools provide Python packages, command-line programs, and Docker images with consistent interfaces. Together, BioSimulators makes it easier to run simulations. BioSimulators is powered by several conventions including SED-ML, KiSAO, COMBINE, and other standards.