GROMACS is a versatile package to perform Molecular Dynamics. Although at the beginning, it was designed for biochemical molecules like proteins, lipids and nucleic acids, now many scientits are using it for research on non-biological systems because is really fast at calculating the nonbonded interactions.
The GROMACS project began at the University of Groningen, Netherlands. The original goal was to construct a dedicated parallel computer system for molecular simulations, based on a ring architecture. Nowadays is maintained by contributors in universities and research centers worldwide and has become one of the most popular software packages in Molecular Dynamics area.