GRASS GIS, commonly referred to as GRASS (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 currently used in academic and commercial settings around the world, as well as by many governmental agencies and environmental consulting companies. It is a founding member of the Open Source Geospatial Foundation (OSGeo).
TerrSet is an integrated geospatial software for monitoring and modeling the earth system. The TerrSet software incorporates the IDRISI GIS Analysis and IDRISI Image Processing tools along with a constellation of modeling environments to analyze land change, image time series, ecosystem services, habitat and biodiversity, climate impacts, and REDD. There are costs involved with this application.