5. GRASS GIS
Supported OS: Windows, Mac OS 10, Linux
GRASS (Geographic Resources Analysis Support System) GIS is widely used software in government organizations such as NASA, because the abundance of tools that offer spatio-temporal data managing, image processing, visualization… It is free and since many people work on it, it is constantly being upgraded and tools are being added and improved. There are around 350 tools for creating and storing managing spatial data, dealing with both vector and raster data, rendering maps, digitizing, calculating, etc.
