Quantum GIS (QGIS) is a cross-platform Geographic Information System (GIS). It offers support for vector and raster formats, including spatially enabled tables in PostgreSQL using PostGIS, common GIS vector formats such as Shapefiles, and geo-referenced rasters (TIFF, PNG, and GEOTIFF). Many plugins are available to dynamically add new functionality. Viewing of GRASS layers (vector and raster) is provided by a plugin. GRASS vector layers can be edited in QGIS.