The files in the src, lib, toolbin, examples, doc and man
  directories (folders) and any subdirectories (sub-folders)
  thereof are part of GPL Ghostscript.

  The files in the Resource directory and any subdirectories thereof
  are also part of GPL Ghostscript, with the explicit exception of
  the files in the CMap subdirectory. The CMap files are copyright
  Adobe Systems Incorporated and covered by a separate license
  which permits only verbatim distribution.

  GPL Ghostscript is free software; you can redistribute it and/or
  modify it under the terms of version 2 of the GNU General Public
  License as published by the Free Software Foundation.

  GPL Ghostscript is distributed in the hope that it will be
  useful, but WITHOUT ANY WARRANTY; without even the implied warranty
  of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  General Public License for more details.

  You should have received a copy of the GNU General Public License
  along with this program so you can know your rights and responsibilities.
  It should be in a file named doc/COPYING. If not, write to the
  Free Software Foundation, Inc., 59 Temple Place Suite 330, Boston, MA
  02111-1307, USA.

 ---

  GPL Ghostscript contains an implementation of techniques covered 
  by US Patents 5,055,942 and 5,917,614, and corresponding
  international patents. These patents are licensed for use with
  GPL Ghostscript under the following grant:

  Whereas, Raph Levien (hereinafter "Inventor") has obtained patent
  protection for related technology (hereinafter "Patented
  Technology"), Inventor wishes to aid the the GNU free software
  project in achieving its goals, and Inventor also wishes to
  increase public awareness of Patented Technology, Inventor hereby
  grants a fully paid up, nonexclusive, royalty free license to
  practice the patents listed below ("the Patents") if and only if
  practiced in conjunction with software distributed under the
  terms of any version of the GNU General Public License as
  published by the Free Software Foundation, 59 Temple Place, Suite
  330, Boston, MA 02111. Inventor reserves all other rights,
  including without limitation, licensing for software not
  distributed under the GNU General Public License.

   5055942 Photographic image reproduction device using digital 
           halftoning to screen images allowing adjustable coarseness

   5917614 Method and apparatus for error diffusion screening of 
           images with improved smoothness in highlight and shadow 
           regions