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. GMT requires netcdf, available at SlackBuilds.org. In order to build GMT, there are a number of required archives: GMT4.4.0_doc.tar.bz2 GMT4.4.0_share.tar.bz2 GMT4.4.0_src.tar.bz2 GMT4.4.0_suppl.tar.bz2 GMT4.4.0_triangle.tar.bz2 (if you require Shewchuk's triangulation routine (see below)). These must all be downloaded and placed in the same directory as the SlackBuild script (as with any source). There are a number of different resolution coastline files available for GMT, and their size on disk varies from <2MB (low) to 61.7MB (full). They come in 3 separate archives: GSHHS1.10_coast.tar.bz2 GSHHS1.10_high.tar.bz2 GSHHS1.10_full.tar.bz2 The first contains the low, intermediate and coarse resolutions, the second the high resolution, and the third the full resolution. I prefer to have all of them installed (disk space is cheap), but you may not. Therefore, by default, all three sets will be installed, unless you choose otherwise in the script. e.g. ${COASTS:-"coast"} would install only the low, intermediate and coarse resolutions. A minimum of GSHHS1.10_coast.tar.bz2 is required. To download all the files, the following works: wget ftp://ftp.soest.hawaii.edu/gmt/GMT4.4.0_{doc,share,src,suppl,triangle}.tar.bz2 ftp://ftp.soest.hawaii.edu/gmt/GSHHS1.10_{full,coast,high}.tar.bz2 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 (in $PKG/src/README.TRIANGLE) first. This script enables the (much faster) Shewchuk triangulation routine by default; should you need to change this behaviour, set SHEWCHUK to "no" in the build script.