APPENDIX
OPEN SOURCE LICENSE
Copyright (C) 1989, 1991 Free Software Foundation, Inc., 51
Franklin Street, Fifth Floor, Boston, MA 021 10-1301 USA
Everyone is permitted to copy and distribute verbatim copies of
this license document, but changing it is not allowed.
The licenses for most software are designed to take away your
freedom to share and change it. By contrast, the GNU General
Public License is intended to guarantee your freedom to share
and change free software - to make sure the software is free for
all its users. This General Public License applies to most of the
Free Software Foundation's software and to any other program
whose authors commit to using it. (Some other free software
foundation software is covered by the GNU Lesser General Public
License instead.) You can apply it to your programs, too.
When we speak of free software, we are referring to freedom, not
price. Our General Public Licenses are designed to make sure that
you have the freedom to distribute copies of free software (and
charge for this service if you wish), that you receive source code
or can get it if you want it, that you can change the software or
use pieces of it in new free programs; and that you know you can
do these things.
To protect your rights, we need to make restrictions that forbid
anyone to deny you these rights or to ask you to surrender the
rights. These restrictions translate to certain responsibilities for
you if you distribute copies of the software, or if you modify it.
For example, if you distribute copies of such a program, whether
gratis or for a fee, you must give the recipients all the rights that
you have. You must make sure that they, too, receive or can get
the source code. And you must show them these terms so they
know their rights.
We protect your rights with two steps: (1) copyright the soft-
ware, and (2) offer you this license which gives you legal permis-
sion to copy, distribute and/or modify the software.
Also, for each author's protection and ours, we want to make cer-
tain that everyone understands that there is no warranty for this
free software. If the software is modified by someone else and
passed on, we want its recipients to know that what they have is
not the original, so that any problems introduced by others will
not reflect on the original authors' reputations.
Finally, any free program is threatened constantly by software
patents. We wish to avoid the danger that redistributors of a free
program will individually obtain patent licenses, in effect making
96
GNU GENERAL PUBLIC LICENSE
Preamble
Version 2, June 1991
the program proprietary. To prevent this, we have made it clear
that any patent must be licensed for everyone's free use or not
licensed at all.
The precise terms and conditions for copying, distribution and
modification follow.
GNU GENERAL PUBLIC LICENSE
TERMS AND CONDITIONS FOR COPYING, DISTRIBUTION
AND MODIFICATION
0. This license applies to any program or other work which con-
tains a notice placed by the copyright holder saying it may be
distributed under the terms of this General Public License. The
"Program", below, refers to any such program or work, and a
"work based on the Program" means either the Program or any
derivative work under copyright law: that is to say, a work con-
taining the Program or a portion of it, either verbatim or with
modifications and/or translated into another language.
(Hereinafter, translation is included without limitation in the
term "modification".) Each licensee is addressed as "you".
Activities other than copying, distribution and modification
are not covered by this license; they are outside its scope.
The act of running the Program is not restricted, and the out-
put from the program is covered only if its contents constitute
a work based on the program (independent of having been
made by running the program). Whether that is true depends
on what the program does.
1. You may copy and distribute verbatim copies of the program's
source code as you receive it, in any medium, provided that
you conspicuously and appropriately publish on each copy an
appropriate copyright notice and disclaimer of warranty; keep
intact all the notices that refer to this license and to the
absence of any warranty; and give any other recipients of the
program a copy of this license along with the Program.
You may charge a fee for the physical act of transferring a
copy, and you may at your option offer warranty protection in
exchange for a fee.
2. You may modify your copy or copies of the program or any
portion of it, thus forming a work based on the Program, and
copy and distribute such modifications or work under the
terms of section 1 above, provided that you also meet all of
these conditions:
a) You must cause the modified files to carry prominent
notices stating that you changed the files and the date of
any change.