GNU GENERAL PUBLIC LICENSE
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.
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
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
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:
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.
- 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.)
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
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
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:
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.
- 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;
- 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.)
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
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
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.
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
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'
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.
Return to GNU's home page.
FSF & GNU inquiries & questions to email@example.com. Other ways to contact the FSF.
Comments on these web pages to firstname.lastname@example.org, send
other questions to email@example.com.
Copyright notice above.
Free Software Foundation, Inc., 59 Temple Place -
Suite 330, Boston, MA 02111, USA
Updated: Last modified: Sun Jul 15 13:13:30 CEST 2001