The Geographic Resources Analysis Support System, commonly referred to as GRASS, is a Geographic Information System (GIS) providing powerful raster, vector, and geospatial processing engines in a single integrated software suite. GRASS includes tools for spatial modeling, visualization of raster and vector data, management and analysis of geospatial data, and the processing of satellite and aerial imagery. It also provides the capability to produce sophisticated presentation graphics and hardcopy maps. GRASS has now been translated into twenty languages and supports a huge array of data formats.
GRASS is currently used around the world in academic and commercial settings as well as by many governmental agencies and environmental consulting companies. It runs on a variety of popular hardware platforms and is Free open-source software released under the terms of the GNU General Public License.
The GRASS software includes over 400 built-in analysis modules. Additionally, over 100 community supplied modules and toolboxes are available for free from the community wiki site. After 27 years of continuous development GRASS is both the oldest and largest Open Source GIS available. It is easily scriptable and versatile enough to be used both for batch data processing on massively-parallel supercomputers as well as a handy desktop GIS for handheld PDAs or netbooks.
Website: http://grass.osgeo.org
Licence: GNU General Public License (GPL) version 2
Software Version: 6.4.0
Supported Platforms: GNU/Linux, Mac OSX, MS Windows
API Interfaces: C, Python, Bourne Shell
Support: http://grass.osgeo.org/community/