ESPResSo, the Extensible Simulation Package for Research on Soft Matter, is a highly versatile open source simulation package for performing and analyzing scientific molecular dynamics and Monte Carlo many-particle simulations. It is designed as a universal tool for simulating a variety of soft matter systems, especially coarse-grained atomistic or bead-spring models used in physics, chemistry, molecular biology, and process engineering. ESPResSo can be used to simulate polymers, liquid crystals, colloids, polyelectrolytes, ferrofluids, gels, biological systems, DNA, lipid membranes, bacterial motion, and super-capacitors. In coarse-grained models, a group of atoms or molecules is treated as a single bead, allowing researchers to investigate larger time and length scales than would be practical with fully atomistic simulations. ...