GNU GENERAL PUBLIC LICENSE
[ You can view the FSF's "official" version
here, but
this text is identical. ]
Version 2, June 1991
Copyright (C) 1989, 1991 Free Software
Foundation, Inc.
59 Temple Place - Suite 330, Boston, MA 02111-1307, 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 Library
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
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.
3. You may copy and distribute the Program (or a
work based on it, under Section 2) in object code or executable
form under the terms of Sections 1 and 2 above provided that you
also do one of the following:
a) Accompany it with the complete
corresponding machine-readable source code, which must be
distributed under the terms of Sections 1 and 2 above on a
medium customarily used for software interchange; or,
b) Accompany it with a written offer, valid
for at least three years, to give any third party, for a
charge no more than your cost of physically performing source
distribution, a complete machine-readable copy of the
corresponding source code, to be distributed under the terms
of Sections 1 and 2 above on a medium customarily used for
software interchange; or,
c) Accompany it with the information you
received as to the offer to distribute corresponding source
code. (This alternative is allowed only for noncommercial
distribution and only if you received the program in object
code or executable form with such an offer, in accord with
Subsection b above.)
The source code for a work means the preferred
form of the work for making modifications to it. For an
executable work, complete source code means all the source code
for all modules it contains, plus any associated interface
definition files, plus the scripts used to control compilation
and installation of the executable. However, as a special
exception, the source code distributed need not include anything
that is normally distributed (in either source or binary form)
with the major components (compiler, kernel, and so on) of the
operating system on which the executable runs, unless that
component itself accompanies the executable.
If distribution of executable or object code is
made by offering access to copy from a designated place, then
offering equivalent access to copy the source code from the same
place counts as distribution of the source code, even though
third parties are not compelled to copy the source along with
the object code.
4. You may not copy, modify, sublicense, or
distribute the Program except as expressly provided under this
License. Any attempt otherwise to copy, modify, sublicense or
distribute the Program is void, and will automatically terminate
your rights under this License. However, parties who have
received copies, or rights, from you under this License will not
have their licenses terminated so long as such parties remain in
full compliance.
5. You are not required to accept this License,
since you have not signed it. However, nothing else grants you
permission to modify or distribute the Program or its derivative
works. These actions are prohibited by law if you do not accept
this License. Therefore, by modifying or distributing the
Program (or any work based on the Program), you indicate your
acceptance of this License to do so, and all its terms and
conditions for copying, distributing or modifying the Program or
works based on it.
6. Each time you redistribute the Program (or
any work based on the Program), the recipient automatically
receives a license from the original licensor to copy,
distribute or modify the Program subject to these terms and
conditions. You may not impose any further restrictions on the
recipients' exercise of the rights granted herein. You are not
responsible for enforcing compliance by third parties to this
License.
7. If, as a consequence of a court judgment or
allegation of patent infringement or for any other reason (not
limited to patent issues), conditions are imposed on you
(whether by court order, agreement or otherwise) that contradict
the conditions of this License, they do not excuse you from the
conditions of this License. If you cannot distribute so as to
satisfy simultaneously your obligations under this License and
any other pertinent obligations, then as a consequence you may
not distribute the Program at all. For example, if a patent
license would not permit royalty-free redistribution of the
Program by all those who receive copies directly or indirectly
through you, then the only way you could satisfy both it and
this License would be to refrain entirely from distribution of
the Program.
If any portion of this section is held invalid
or unenforceable under any particular circumstance, the balance
of the section is intended to apply and the section as a whole
is intended to apply in other circumstances.
It is not the purpose of this section to induce
you to infringe any patents or other property right claims or to
contest validity of any such claims; this section has the sole
purpose of protecting the integrity of the free software
distribution system, which is implemented by public license
practices. Many people have made generous contributions to the
wide range of software distributed through that system in
reliance on consistent application of that system; it is up to
the author/donor to decide if he or she is willing to distribute
software through any other system and a licensee cannot impose
that choice.
This section is intended to make thoroughly
clear what is believed to be a consequence of the rest of this
License.
8. If the distribution and/or use of the Program
is restricted in certain countries either by patents or by
copyrighted interfaces, the original copyright holder who places
the Program under this License may add an explicit geographical
distribution limitation excluding those countries, so that
distribution is permitted only in or among countries not thus
excluded. In such case, this License incorporates the limitation
as if written in the body of this License.
9. The Free Software Foundation may publish
revised and/or new versions of the General Public License from
time to time. Such new versions will be similar in spirit to the
present version, but may differ in detail to address new
problems or concerns.
Each version is given a distinguishing version
number. If the Program specifies a version number of this
License which applies to it and "any later version", you have
the option of following the terms and conditions either of that
version or of any later version published by the Free Software
Foundation. If the Program does not specify a version number of
this License, you may choose any version ever published by the
Free Software Foundation.
10. If you wish to incorporate parts of the
Program into other free programs whose distribution conditions
are different, write to the author to ask for permission. For
software which is copyrighted by the Free Software Foundation,
write to the Free Software Foundation; we sometimes make
exceptions for this. Our decision will be guided by the two
goals of preserving the free status of all derivatives of our
free software and of promoting the sharing and reuse of software
generally.
NO WARRANTY
11. BECAUSE THE PROGRAM IS LICENSED FREE OF
CHARGE, THERE IS NO WARRANTY FOR THE PROGRAM, TO THE EXTENT
PERMITTED BY APPLICABLE LAW. EXCEPT WHEN OTHERWISE STATED IN
WRITING THE COPYRIGHT HOLDERS AND/OR OTHER PARTIES PROVIDE THE
PROGRAM "AS IS" WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESSED
OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
PURPOSE. THE ENTIRE RISK AS TO THE QUALITY AND PERFORMANCE OF
THE PROGRAM IS WITH YOU. SHOULD THE PROGRAM PROVE DEFECTIVE, YOU
ASSUME THE COST OF ALL NECESSARY SERVICING, REPAIR OR
CORRECTION.
12. IN NO EVENT UNLESS REQUIRED BY APPLICABLE
LAW OR AGREED TO IN WRITING WILL ANY COPYRIGHT HOLDER, OR ANY
OTHER PARTY WHO MAY MODIFY AND/OR REDISTRIBUTE THE PROGRAM AS
PERMITTED ABOVE, BE LIABLE TO YOU FOR DAMAGES, INCLUDING ANY
GENERAL, SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING
OUT OF THE USE OR INABILITY TO USE THE PROGRAM (INCLUDING BUT
NOT LIMITED TO LOSS OF DATA OR DATA BEING RENDERED INACCURATE OR
LOSSES SUSTAINED BY YOU OR THIRD PARTIES OR A FAILURE OF THE
PROGRAM TO OPERATE WITH ANY OTHER PROGRAMS), EVEN IF SUCH HOLDER
OR OTHER PARTY HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
DAMAGES.
END OF TERMS AND CONDITIONS
How to Apply These Terms to Your New Programs
If you develop a new program, and you want it to
be of the greatest possible use to the public, the best way to
achieve this is to make it free software which everyone can
redistribute and change under these terms.
To do so, attach the following notices to the
program. It is safest to attach them to the start of each source
file to most effectively convey the exclusion of warranty; and
each file should have at least the "copyright" line and a
pointer to where the full notice is found.
one line to give the
program's name and an idea of what it does.
Copyright (C) yyyy name of author
This program is free
software; you can redistribute it and/or modify it under the
terms of the GNU General Public License as published by the
Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
This program 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; if not, write to the Free Software Foundation,
Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
Also add information on how to contact you by
electronic and paper mail.
If the program is interactive, make it output a
short notice like this when it starts in an interactive mode:
Gnomovision version
69, Copyright (C) year name of author Gnomovision comes with
ABSOLUTELY NO WARRANTY; for details type `show w'. This is
free software, and you are welcome to redistribute it under
certain conditions; type `show c' for details.
The hypothetical commands `show w' and `show c'
should show the appropriate parts of the General Public License.
Of course, the commands you use may be called something other
than `show w' and `show c'; they could even be mouse-clicks or
menu items--whatever suits your program.
You should also get your employer (if you work
as a programmer) or your school, if any, to sign a "copyright
disclaimer" for the program, if necessary. Here is a sample;
alter the names:
Yoyodyne, Inc., hereby disclaims all copyright
interest in the program `Gnomovision' (which makes passes at
compilers) written by James Hacker.
signature of Ty Coon, 1 April 1989
Ty Coon, President of Vice
This General Public License does not permit
incorporating your program into proprietary programs. If your
program is a subroutine library, you may consider it more useful
to permit linking proprietary applications with the library. If
this is what you want to do, use the GNU Library General Public
License instead of this License. |