GPL-2.0.txt

The GNU General Public License (GPL-2.0)
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 a brief idea of what it does.
    Copyright (C) {{ year }} {{ organization }}

    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.