Powerful open-source geospatial processing engine for large-scale GIS, remote sensing and terrain analysis.
GRASS GIS is a long-established open-source geographic information system and geospatial processing engine, supporting raster, vector, image processing, time series analysis, hydrological analysis and ecological modelling. It can be used on its own or as a processing toolbox within QGIS.
Use cases: GIS spatial analysis, terrain analysis, hydrological modelling, remote sensing processing, ecological spatial modelling
Recommended combination: QGIS + GRASS GIS
