It is licensed and released as free and open-source software under the GNU General Public License (GPL). It runs on multiple operating systems, including , Windows and Linux. Users can interface with the software features through a graphical user interface (GUI) or by "plugging into" GRASS via other software such as QGIS. They can also interface with the modules directly through a bespoke shell that the application launches or by calling individual modules directly from a standard shell. The latest stable release version (LTS) is GRASS GIS 7, which is available since 2015.