What is GMT?
GMT is an open source collection of about 80 command-line tools for manipulating geographic and Cartesian data sets (including filtering, trend fitting, gridding, projecting, etc.) and producing PostScript illustrations ranging from simple x–y plots via contour maps to artificially illuminated surfaces and 3D perspective views; the GMT supplements add another 40 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. GMT is developed and maintained by Paul Wessel, Walter H. F. Smith, Remko Scharroo, Joaquim Luis and Florian Wobbe, with help from a global set of volunteers. and is supported by the National Science Foundation. It is released under the GNU Lesser General Public License version 3 or any later version.
The GMT World Domination
Considering its flexibility at no charge, people worldwide are using GMT in their work and at home. Most users of GMT are Earth or ocean scientists, but there are apparently no limits to the kind of applications that may benefit from GMT: We know GMT is used in medical research, engineering, physics, mathematics, social and biological sciences, and by geographers, fisheries institutes, oil companies, a wide range of government agencies, and last but not least innumerable hobbyists.
The map above illustrates the spreading of the current GMT release around the world based on web traffic. Each colored circle in the map above represents a 15×15 arc minute block with one or more users who downloaded GMT. Download geolocation is based on MaxMind’s freely available GeoLite data.