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 transforma-
tions and comes with support data such as 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.