QGIS (formerly Quantum GIS) is a user-friendly, cross-platform Geographic Information System (GIS) application with support for Linux, Unix, MacOS X and Windows. News updates are available from the QGIS blog.
QGIS supports numerous vector, raster, and database formats and provides numerous features for exploring, creating, analyzing, converting and exporting geospatial data. The core functions can also be extended through external plugins written in Python.
QGIS is an official project of the Open Source Geospatial Foundation (OSGeo) and is licensed under the GNU General Public License.