GRASS GISGRASS GIS (Geographic Resources Analysis Support System), is a free and open source Geographic Information System (GIS) software suite used for geospatial data management and analysis, image processing, graphics and maps production, spatial modeling, and visualization. GRASS GIS is used by many governmental agencies and environmental consulting companies worldwide.
Google EarthSoftware from Google that allows you to explore 3D buildings, imagery, terrain, cities, places and local businesses. You can also access the Google Maps Blog and the Google Earth help forum.
Quantum GIS (QGIS)QGIS is a professional GIS application designed to visualize, manage, edit, analyse data, and compose printable maps. QGIS is a user friendly Open Source Geographic Information System (GIS) licensed under the GNU General Public License.
WebGIS (QGIS)WebGIS.com contains extensive map coverage for technical applications including Air Dispersion Modeling, Human Health & Ecological Risk Assessment and Terrain Processing to facilitate modeling. WebGIS is where you can find leading information and resources for Geographical Information Systems.