praat/main/GNU_General_Public_License.txt

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 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.