Generic Mapping Tools (GMT) is an open source collection of ~60 tools for manipulating geographic and Cartesian data sets (including filtering, trend fitting, gridding, projecting, etc.) and producing Encapsulated PostScript File (EPS) illustrations ranging from simple x-y plots via contour maps to artificially illuminated surfaces and 3-D perspective views. GMT supports ~30 map projections and transformations and comes with support data such as GSHHS coastlines, rivers, and political boundaries. GMT is developed and maintained by Paul Wessel and Walter H. F. Smith with help from a global set of volunteers, and is supported by the National Science Foundation. It is released under the GNU General Public License. Please note, Shewchuk's triangulation routine used in some parts of GMT is not distributed under the GNU Public Licence. If you work for a for-profit organisation, you should read Shewchuk's copyright statement first (you can find it at http://gmt.soest.hawaii.edu/gmt/README.TRIANGLE). This script enables the (much faster) Shewchuk triangulation routine by by default; should you need to change this behaviour, set SHEWCHUK to "no" in the build script. gdal is an optional dependency.