(no commit message)

[perl5.git] / pod / perlgpl.pod

=head1 NAME

perlgpl - the GNU General Public License, version 1

=head1 SYNOPSIS

 You can refer to this document in Pod via "L<perlgpl>"
 Or you can see this document by entering "perldoc perlgpl"

=head1 DESCRIPTION

Perl is free software; you can redistribute it and/or modify
it under the terms of either:

        a) the GNU General Public License as published by the Free
        Software Foundation; either version 1, or (at your option) any
        later version, or

        b) the "Artistic License" which comes with this Kit.

This is the B<"GNU General Public License, version 1">.
It's here so that modules, programs, etc., that want to declare
this as their distribution license can link to it.

For the Perl Artistic License, see L<perlartistic>.

=cut

# Because the following document's language disallows "changing"
# it, we haven't gone thru and prettied it up with =item's or
# anything.  It's good enough the way it is.

=head1 GNU GENERAL PUBLIC LICENSE

                    GNU GENERAL PUBLIC LICENSE
                     Version 1, February 1989
 
  Copyright (C) 1989 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 license agreements of most software companies try to keep users
 at the mercy of those companies.  By contrast, our 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.  The
 General Public License applies to the Free Software Foundation's
 software and to any other program whose authors commit to using it.
 You can use it for your programs, too.
 
   When we speak of free software, we are referring to freedom, not
 price.  Specifically, the General Public License is designed to make
 sure that you have the freedom to give away or sell copies of free
 software, 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 a 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 tell them 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.
 
   The precise terms and conditions for copying, distribution and
 modification follow.
  
                    GNU GENERAL PUBLIC LICENSE
    TERMS AND CONDITIONS FOR COPYING, DISTRIBUTION AND MODIFICATION
 
   0. This License Agreement 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 work containing the
 Program or a portion of it, either verbatim or with modifications.  Each
 licensee is addressed as "you".
 
   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
 General Public License and to the absence of any warranty; and give any
 other recipients of the Program a copy of this General Public License
 along with the Program.  You may charge a fee for the physical act of
 transferring a copy.
 
   2. You may modify your copy or copies of the Program or any portion of
 it, and copy and distribute such modifications under the terms of Paragraph
 1 above, provided that you also do the following:
 
     a) cause the modified files to carry prominent notices stating that
     you changed the files and the date of any change; and
 
     b) cause the whole of any work that you distribute or publish, that
     in whole or in part contains the Program or any part thereof, either
     with or without modifications, to be licensed at no charge to all
     third parties under the terms of this General Public License (except
     that you may choose to grant warranty protection to some or all
     third parties, at your option).
 
     c) If the modified program normally reads commands interactively when
     run, you must cause it, when started running for such interactive use
     in the simplest and most usual 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 General
     Public License.
 
     d) 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.
 
 Mere aggregation of another independent work with the Program (or its
 derivative) on a volume of a storage or distribution medium does not bring
 the other work under the scope of these terms.
  
   3. You may copy and distribute the Program (or a portion or derivative of
 it, under Paragraph 2) in object code or executable form under the terms of
 Paragraphs 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
     Paragraphs 1 and 2 above; or,
 
     b) accompany it with a written offer, valid for at least three
     years, to give any third party free (except for a nominal charge
     for the cost of distribution) a complete machine-readable copy of the
     corresponding source code, to be distributed under the terms of
     Paragraphs 1 and 2 above; or,
 
     c) accompany it with the information you received as to where the
     corresponding source code may be obtained.  (This alternative is
     allowed only for noncommercial distribution and only if you
     received the program in object code or executable form alone.)
 
 Source code for a work means the preferred form of the work for making
 modifications to it.  For an executable file, complete source code means
 all the source code for all modules it contains; but, as a special
 exception, it need not include source code for modules which are standard
 libraries that accompany the operating system on which the executable
 file runs, or for standard header files or definitions files that
 accompany that operating system.
 
   4. You may not copy, modify, sublicense, distribute or transfer the
 Program except as expressly provided under this General Public License.
 Any attempt otherwise to copy, modify, sublicense, distribute or transfer
 the Program is void, and will automatically terminate your rights to use
 the Program under this License.  However, parties who have received
 copies, or rights to use copies, from you under this General Public
 License will not have their licenses terminated so long as such parties
 remain in full compliance.
 
   5. By copying, distributing or modifying 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.
 
   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.
  
   7. 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 the 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
 the license, you may choose any version ever published by the Free Software
 Foundation.
 
   8. 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
 
   9. 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.
 
   10. 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
 
        Appendix: 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 humanity, 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) 19yy  <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 1, 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) 19xx 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 a sample; alter the names:
 
   Yoyodyne, Inc., hereby disclaims all copyright interest in the
   program `Gnomovision' (a program to direct compilers to make passes
   at assemblers) written by James Hacker.
 
   <signature of Ty Coon>, 1 April 1989
   Ty Coon, President of Vice
 
 That's all there is to it!

=cut