[10] It is free, open-source software released under the GNU Lesser General Public License (LGPL)[3] (GPL prior to Version 4.6).

The original goal was to construct a dedicated parallel computer system for molecular simulations, based on a ring architecture (since superseded by modern hardware designs).

It contains a script to convert molecular coordinates from Protein Data Bank (PDB) files into the formats it uses internally.

GPU support has been expanded and improved over the years,[12] and, in Version 2023, GROMACS has CUDA,[13] OpenCL, and SYCL backends for running on GPUs of AMD, Apple, Intel, and Nvidia, often with great acceleration compared to CPU.

These include "Gromacs Runs On Most of All Computer Systems", "Gromacs Runs One Microsecond At Cannonball Speeds", "Good ROcking Metal Altar for Chronical Sinner", "Working on GRowing Old MAkes el Chrono Sweat", and "Great Red Owns Many ACres of Sand".