GRASS GIS (Geographic Resources Analysis Support System) is an open-source geographic information system used for data management, analysis, and visualization. It supports various spatial data formats and provides tools for tasks such as raster and vector analysis, geostatistics, and 3D modeling. Developed by the U.S. Army Corps of Engineers in the 1980s, GRASS GIS is widely used in academia, research, and industry for environmental modeling, urban planning, and resource management. Its modular architecture allows users to extend its capabilities through plugins and scripts, making it a flexible choice for geospatial analysis.