- Open Geospatial Consortium (OGC)
- Open Source Geospatial Foundation
- Quantum GIS (QGIS)
- Forestry GIS (fGIS)
- TatukGIS
- MapWindow GIS
- MapTools
- MapServer: originally developed by the University of Minnesota
- MapLab: DM Solutions Group
- PostGIS: Refractions Research
- PostgreSQL: PostgreSQL Research Development Group
- uDig: Refractions Research
- JUMP Unified Mapping Platform: Vivid Solutions
- GRASS GIS: Geographic Resources Analysis Support System Geographic Information Systems (GIS) software
- GRASS Development Team
- Shapefile C Library
- GDAL: Geospatial Data Abstraction Library
- GeoTools
- MapBuilder