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.

This requires netcdf.

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:
  GSHHS2.0.2_coast.tar.bz2 GSHHS2.0.2_high.tar.bz2 GSHHS2.0.2_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, all 
three sets will be installed by default unless you choose otherwise in the 
script, e.g. setting "COASTS=coast" in the environment would install only the 
low, intermediate, and coarse resolutions. 

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 (in
src/README.TRIANGLE).  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.

