PLplot is a library of C functions that are useful for making scientific
plots from a program written in C or Fortran.  The PLplot library can be
used to create standard x-y plots, semilog plots, log-log plots, contour
plots, 3D plots, mesh plots, bar charts and pie charts.  Multiple graphs (of
the same or different sizes) may be placed on a single page with multiple
lines in each graph.  There are almost 2000 characters in the extended
character set.  This includes four different fonts, the Greek alphabet and a
host of mathematical, musical, and other symbols.  A variety of output
devices are supported and new devices can be easily added by writing a small
number of device dependent routines.  

PLplot is free software primarily licensed under the LGPL (see
http://www.gnu.org/licenses/lgpl.html). It is currently known to work on the
following systems: Linux, SUNOS, Mac OSX, IRIX, Cygwin, Windows, and MS-DOS,
with more expected. 
