GNU GENERAL PUBLIC LICENSE
Version 2, June 1991
Copyright (C)1989, 1991 Free Software Foundation, Inc. 51
Franklin Street,Fifth Floor, Boston, MA 02110-1301, USA
Everyone is permitted to copy and distribute verbatim copies
of this license document, but changing it is not allowed.
Preamble
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 software, and (2)offer you this license which
gives you legal permission to copy, distribute and/or modify
the software. Also, for each author’s protection and ours, we
want to make certain 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 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.
TERMS AND CONDITIONS FOR COPYING,
DISTRIBUTION AND MODIFICATION
Version 2, June 1991 Copyright (C) 1989, 1991 Free
Software Foundation, Inc. 51 Franklin S
0. This License applies to any program or other work which
contains 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 containing 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
output 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.
b) You must cause any work that you distribute or
publish, that in whole or in part contains or is derived
from the Program or any part thereof, to be licensed
as a whole at no charge to all third parties under the
terms of this License.
c) If the modified program normally reads commands
interactively when run,you must cause it, when started
running for such interactive use in the most ordinary
way, to print or display an announcement including
an appropriate copyright notice and a notice that
there is no warranty (or else, saying that you provide a
warranty) and that users may redistribute the program
under these conditions, and telling the user how to
view a copy of this License. (Exception:if the Program
itself is interactive but does not normally print such an
announcement, your work based on the Program is
not required to print an announcement.)
These requirements apply to the modified work as a whole.
If identifiable sections of that work are not derived from the
Program, and can be reasonably considered independent
and separate works in themselves, then this License, and its
terms, do not apply to those sections when you distribute
them as separate works. But when you distribute the same
sections as part of a whole which is a work based on the
Program, the distribution of the whole must be on the terms
of this License, whose permissions for other licensees
extend to the entire whole, and thus to each and every part
regardless of who wrote it.
Thus, it is not the intent of this section to claim rights or
contest your rights to work written entirely by you ; rather,
the intent is to exercise the right to control the distribution
of derivative or collective works based on the Program.
In addition, mere aggregation of another work not based
on the Program with the Program (or with a work based
on the Program)on a volume of a storage or distribution
medium does not bring the other work under the scope of
this License.
