GMT is a collection of about 100 command-line tools for manipulating geographic and Cartesian data sets (including filtering, trend fitting, gridding, projecting, etc.) and producing high-quality illustrations ranging from simple x-y plots via contour maps to artificially illuminated surfaces, 3D perspective views and animations. The GMT supplements add another 50 more specialized and discipline-specific tools. GMT supports over 30 map projections and transformations and requires support data such as GSHHG coastlines, rivers, and political boundaries and optionally DCW country polygons.