What is GRASS ?

GRASS - Geographic Resources Analysis Support System is a general GIS supporting processing, analysis and display of raster, vector, site and imagery data, geospatial simulations and visualization.

For a general introduction, see the GRASS First Time User Page.

Overview of GRASS versions currently available:

GRASS is an Open source sofware released under the GNU General Public Licence - it is therefore free with protection of the authors' rights. With its 1.5 million lines of C code, it is one of the largest Open source projects.