GNU GENERAL PUBLIC LICENSE
Version 2, June 1991
Copyright (C) 1989, 1991 Free Software Foundation, Inc.
51 Franklin St, Fifth Floor, Boston, MA 02110, 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
License is intended to guarantee your freedom to share and
software--to make sure the software is free for all its users.
General Public License applies to most of the Free Software
Foundation's software and to any other program whose authors
using it. (Some other Free Software Foundation software is
the GNU Library General Public License instead.) You can apply
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
have the freedom to distribute copies of free software (and
this service if you wish), that you receive source code or can
if you want it, that you can change the software or use pieces
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
These restrictions translate to certain responsibilities for 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
you have. You must make sure that they, too, receive or can get
source code. And you must show them these terms so they know
We protect your rights with two steps: (1) copyright the
(2) offer you this license which gives you legal permission to
distribute and/or modify the software.
Also, for each author's protection and ours, we want to make
that everyone understands that there is no warranty for this
software. If the software is modified by someone else and passed
want its recipients to know that what they have is not the
that any problems introduced by others will not reflect on the
Finally, any free program is threatened constantly by software
patents. We wish to avoid the danger that redistributors of a
program will individually obtain patent licenses, in effect
program proprietary. To prevent this, we have made it clear that
patent must be licensed for everyone's free use or not licensed
The precise terms and conditions for copying, distribution and
GNU GENERAL PUBLIC LICENSE
TERMS AND CONDITIONS FOR COPYING, DISTRIBUTION AND MODIFICATION
0. This License applies to any program or other work which
a notice placed by the copyright holder saying it may be
under the terms of this General Public License. The "Program",
refers to any such program or work, and a "work based on the
means either the Program or any derivative work under copyright
that is to say, a work containing the Program or a portion of
either verbatim or with modifications and/or translated into
language. (Hereinafter, translation is included without
the term "modification".) Each licensee is addressed as "you".
Activities other than copying, distribution and modification are
covered by this License; they are outside its scope. The act of
running the Program is not restricted, and the output from the
is covered only if its contents constitute a work based on the
Program (independent of having been made by running the
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
copyright notice and disclaimer of warranty; keep intact all the
notices that refer to this License and to the absence of any
and give any other recipients of the Program a copy of this
along with the Program.
You may charge a fee for the physical act of transferring a
you may at your option offer warranty protection in exchange for
2. You may modify your copy or copies of the Program or any
of it, thus forming a work based on the Program, and copy and
distribute such modifications or work under the terms of Section
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
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
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
a warranty) and that users may redistribute the program under
these conditions, and telling the user how to view a copy of
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
and can be reasonably considered independent and separate works
themselves, then this License, and its terms, do not apply to
sections when you distribute them as separate works. But when
distribute the same sections as part of a whole which is a work
on the Program, the distribution of the whole must be on the
this License, whose permissions for other licensees extend to
entire whole, and thus to each and every part regardless of who
Thus, it is not the intent of this section to claim rights or
your rights to work written entirely by you; rather, the intent
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
with the Program (or with a work based on the Program) on a
a storage or distribution medium does not bring the other work
the scope of this License.
3. You may copy and distribute the Program (or a work based on
under Section 2) in object code or executable form under the
Sections 1 and 2 above provided that you also do one of the
a) Accompany it with the complete corresponding machine-readable
source code, which must be distributed under the terms of
1 and 2 above on a medium customarily used for software
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
customarily used for software interchange; or,
c) Accompany it with the information you received as to the
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
making modifications to it. For an executable work, complete
code means all the source code for all modules it contains, plus
associated interface definition files, plus the scripts used to
control compilation and installation of the executable. However,
special exception, the source code distributed need not include
anything that is normally distributed (in either source or
form) with the major components (compiler, kernel, and so on) of
operating system on which the executable runs, unless that
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
compelled to copy the source along with the object code.
4. You may not copy, modify, sublicense, or distribute the
except as expressly provided under this License. Any attempt
otherwise to copy, modify, sublicense or distribute the Program
void, and will automatically terminate your rights under this
However, parties who have received copies, or rights, from you
this License will not have their licenses terminated so long as
parties remain in full compliance.
5. You are not required to accept this License, since you have
signed it. However, nothing else grants you permission to modify
distribute the Program or its derivative works. These actions
prohibited by law if you do not accept this License. Therefore,
modifying or distributing the Program (or any work based on the
Program), you indicate your acceptance of this License to do so,
all its terms and conditions for copying, distributing or
the Program or works based on it.
6. Each time you redistribute the Program (or any work based on
Program), the recipient automatically receives a license from
original licensor to copy, distribute or modify the Program
these terms and conditions. You may not impose any further
restrictions on the recipients' exercise of the rights granted
You are not responsible for enforcing compliance by third
7. If, as a consequence of a court judgment or allegation of
infringement or for any other reason (not limited to patent
conditions are imposed on you (whether by court order, agreement
otherwise) that contradict the conditions of this License, they
excuse you from the conditions of this License. If you cannot
distribute so as to satisfy simultaneously your obligations
License and any other pertinent obligations, then as a
may not distribute the Program at all. For example, if a patent
license would not permit royalty-free redistribution of the
all those who receive copies directly or indirectly through you,
the only way you could satisfy both it and this License would be
refrain entirely from distribution of the Program.
If any portion of this section is held invalid or unenforceable
any particular circumstance, the balance of the section is
apply and the section as a whole is intended to apply in other
It is not the purpose of this section to induce you to infringe
patents or other property right claims or to contest validity of
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
system; it is up to the author/donor to decide if he or she is
to distribute software through any other system and a licensee
impose that choice.
This section is intended to make thoroughly clear what is
be a consequence of the rest of this License.
8. If the distribution and/or use of the Program is restricted
certain countries either by patents or by copyrighted
original copyright holder who places the Program under this
may add an explicit geographical distribution limitation
those countries, so that distribution is permitted only in or
countries not thus excluded. In such case, this License
the limitation as if written in the body of this License.
9. The Free Software Foundation may publish revised and/or new
of the General Public License from time to time. Such new
be similar in spirit to the present version, but may differ in
address new problems or concerns.
Each version is given a distinguishing version number. If the
specifies a version number of this License which applies to it
later version", you have the option of following the terms and
either of that version or of any later version published by the
Software Foundation. If the Program does not specify a version
this License, you may choose any version ever published by the
10. If you wish to incorporate parts of the Program into other
programs whose distribution conditions are different, write to
to ask for permission. For software which is copyrighted by the
Software Foundation, write to the Free Software Foundation; we
make exceptions for this. Our decision will be guided by the two
of preserving the free status of all derivatives of our free
of promoting the sharing and reuse of software generally.
11. BECAUSE THE PROGRAM IS LICENSED FREE OF CHARGE, THERE IS NO
FOR THE PROGRAM, TO THE EXTENT PERMITTED BY APPLICABLE LAW.
OTHERWISE STATED IN WRITING THE COPYRIGHT HOLDERS AND/OR OTHER
PROVIDE THE PROGRAM "AS IS" WITHOUT WARRANTY OF ANY KIND, EITHER
OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. THE ENTIRE
TO THE QUALITY AND PERFORMANCE OF THE PROGRAM IS WITH YOU.
PROGRAM PROVE DEFECTIVE, YOU ASSUME THE COST OF ALL NECESSARY
REPAIR OR CORRECTION.
12. IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO
WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MAY MODIFY
REDISTRIBUTE THE PROGRAM AS PERMITTED ABOVE, BE LIABLE TO YOU
INCLUDING ANY GENERAL, SPECIAL, INCIDENTAL OR CONSEQUENTIAL
OUT OF THE USE OR INABILITY TO USE THE PROGRAM (INCLUDING BUT
TO LOSS OF DATA OR DATA BEING RENDERED INACCURATE OR LOSSES
YOU OR THIRD PARTIES OR A FAILURE OF THE PROGRAM TO OPERATE WITH
PROGRAMS), EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED
POSSIBILITY OF SUCH DAMAGES.
END OF TERMS AND CONDITIONS