The PLplot package may be distributed under the terms of the GNU General
Public License (GPL), except as noted below.  The text of this license is
given in the file COPYING in the distribution directory.

The PLplot library may be distributed under the terms of the GNU Library
General Public License (LGPL), except as noted below.  The text of this
license is given in the file COPYING.LIB in the distribution directory.

The startup code used in argument handling (utils/plrender.c and
src/plargs.c) is partially derived from "xterm.c" of the X11R5
distribution, and its copyright is reproduced here:

******************************************************************************
Copyright 1987, 1988 by Digital Equipment Corporation, Maynard, Massachusetts,
and the Massachusetts Institute of Technology, Cambridge, Massachusetts.

                        All Rights Reserved

Permission to use, copy, modify, and distribute this software and its 
documentation for any purpose and without fee is hereby granted, 
provided that the above copyright notice appear in all copies and that
both that copyright notice and this permission notice appear in 
supporting documentation, and that the names of Digital or MIT not be
used in advertising or publicity pertaining to distribution of the
software without specific, written prior permission.  

DIGITAL DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING
ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO EVENT SHALL
DIGITAL BE LIABLE FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR
ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS,
WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION,
ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
SOFTWARE.
******************************************************************************

Any file that is explicitly marked as "public domain" is free from any
restriction on distribution.  

Any file that has a explicit copyright notice may be distributed under
the terms of both the GPL and whatever stated conditions accompany the
copyright.

Notes: the intent behind these licenses is to ensure that PLplot continues
to evolve in a positive way, while remaining freely distributable.
Placing the library under the LGPL enables software developers to use the
PLplot library as an integral part of their product, even a commercial
product.  Under the conditions of the LGPL, however, the source code to
the library must remain freely available.  This means that if you modify
the library to better suit your purposes, you are required to distribute
those changes freely to the general PLplot user community.

