GRDSS (Geographic Resources Decision Support System) is an open source GIS based on GRASS (Geographic Resources Analysis Support System) that has functionalities such as raster, topological vector, image processing, graphics production, etc. It operates through a GUI developed in Tcl/Tk under LINUX. GRDSS include options such as Import / Export (of different data formats) including extraction of individual bands from the IRS (Indian Remote Sensing Satellites) data, display, digital image processing, map editing, raster analysis, vector analysis, point analysis, spatial query, geo-visualisation tools etc.