2. gvSIG
Supported OS: Windows, Mac OS 10.4, 10.5, Ubuntu 6.x, Suse 8.2
Not only that gvSig is free open source Desktop software, it is also available for Mobile devices. It is user-friendly and offers a direct access to a great number of raster, vector, database query tools, easy geoprocessing, and also rendering time of big files is very fast. It is also available in many languages.
