GROMACS is a free, open-source molecular dynamics community code mainly designed for simulations of proteins, lipids, and nucleic acids. It is one of the fastest and most popular scientific software packages available, and can run on central processing units (CPUs) and graphics processing units (GPUs). In this session, Mark Abraham (former development manager of GROMACS) will illustrate software development practices that helped build the GROMACS developer community. Mark will be happy to take any questions you might have, e.g. on how to apply similar ideas to the software projects you are working on.