copying

一个类似俄罗斯方块的游戏

                          GNU GENERAL PUBLIC LICENSE
                                   Version 1
                                 February 1989

                              Copyright (C) 1989
                        Free Software Foundation, Inc.
                           675 Massachusetts Avenue
                        Cambridge, Massachusetts 02139

     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 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 such a program, whether gratis or
  for a free, you must give the recipients all the rights that you have.  You
  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 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 the 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 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 the
  operating system.

  4.  You may not copy, modify, sub-license, distribute, or transfer the
  Program except as expressly provided under this General Public License.
  Any attempt otherwise to copy, modify, sub-license, 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, data being rendered inaccurate, 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) <year> <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:

       Free Software Foundation, Inc.
       675 Massachusetts Avenue
       Cambridge, Massachusetts 02139

  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" could 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" (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!