Home | History | Annotate | Download | only in main
      1 		    GNU GENERAL PUBLIC LICENSE
      2 		       Version 2, June 1991
      3 
      4  Copyright (C) 1989, 1991 Free Software Foundation, Inc.
      5      59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
      6  Everyone is permitted to copy and distribute verbatim copies
      7  of this license document, but changing it is not allowed.
      8 
      9 			    Preamble
     10 
     11   The licenses for most software are designed to take away your
     12 freedom to share and change it.  By contrast, the GNU General Public
     13 License is intended to guarantee your freedom to share and change free
     14 software--to make sure the software is free for all its users.  This
     15 General Public License applies to most of the Free Software
     16 Foundation's software and to any other program whose authors commit to
     17 using it.  (Some other Free Software Foundation software is covered by
     18 the GNU Library General Public License instead.)  You can apply it to
     19 your programs, too.
     20 
     21   When we speak of free software, we are referring to freedom, not
     22 price.  Our General Public Licenses are designed to make sure that you
     23 have the freedom to distribute copies of free software (and charge for
     24 this service if you wish), that you receive source code or can get it
     25 if you want it, that you can change the software or use pieces of it
     26 in new free programs; and that you know you can do these things.
     27 
     28   To protect your rights, we need to make restrictions that forbid
     29 anyone to deny you these rights or to ask you to surrender the rights.
     30 These restrictions translate to certain responsibilities for you if you
     31 distribute copies of the software, or if you modify it.
     32 
     33   For example, if you distribute copies of such a program, whether
     34 gratis or for a fee, you must give the recipients all the rights that
     35 you have.  You must make sure that they, too, receive or can get the
     36 source code.  And you must show them these terms so they know their
     37 rights.
     38 
     39   We protect your rights with two steps: (1) copyright the software, and
     40 (2) offer you this license which gives you legal permission to copy,
     41 distribute and/or modify the software.
     42 
     43   Also, for each author's protection and ours, we want to make certain
     44 that everyone understands that there is no warranty for this free
     45 software.  If the software is modified by someone else and passed on, we
     46 want its recipients to know that what they have is not the original, so
     47 that any problems introduced by others will not reflect on the original
     48 authors' reputations.
     49 
     50   Finally, any free program is threatened constantly by software
     51 patents.  We wish to avoid the danger that redistributors of a free
     52 program will individually obtain patent licenses, in effect making the
     53 program proprietary.  To prevent this, we have made it clear that any
     54 patent must be licensed for everyone's free use or not licensed at all.
     55 
     56   The precise terms and conditions for copying, distribution and
     57 modification follow.
     58 
     59 		    GNU GENERAL PUBLIC LICENSE
     60    TERMS AND CONDITIONS FOR COPYING, DISTRIBUTION AND MODIFICATION
     61 
     62   0. This License applies to any program or other work which contains
     63 a notice placed by the copyright holder saying it may be distributed
     64 under the terms of this General Public License.  The "Program", below,
     65 refers to any such program or work, and a "work based on the Program"
     66 means either the Program or any derivative work under copyright law:
     67 that is to say, a work containing the Program or a portion of it,
     68 either verbatim or with modifications and/or translated into another
     69 language.  (Hereinafter, translation is included without limitation in
     70 the term "modification".)  Each licensee is addressed as "you".
     71 
     72 Activities other than copying, distribution and modification are not
     73 covered by this License; they are outside its scope.  The act of
     74 running the Program is not restricted, and the output from the Program
     75 is covered only if its contents constitute a work based on the
     76 Program (independent of having been made by running the Program).
     77 Whether that is true depends on what the Program does.
     78 
     79   1. You may copy and distribute verbatim copies of the Program's
     80 source code as you receive it, in any medium, provided that you
     81 conspicuously and appropriately publish on each copy an appropriate
     82 copyright notice and disclaimer of warranty; keep intact all the
     83 notices that refer to this License and to the absence of any warranty;
     84 and give any other recipients of the Program a copy of this License
     85 along with the Program.
     86 
     87 You may charge a fee for the physical act of transferring a copy, and
     88 you may at your option offer warranty protection in exchange for a fee.
     89 
     90   2. You may modify your copy or copies of the Program or any portion
     91 of it, thus forming a work based on the Program, and copy and
     92 distribute such modifications or work under the terms of Section 1
     93 above, provided that you also meet all of these conditions:
     94 
     95     a) You must cause the modified files to carry prominent notices
     96     stating that you changed the files and the date of any change.
     97 
     98     b) You must cause any work that you distribute or publish, that in
     99     whole or in part contains or is derived from the Program or any
    100     part thereof, to be licensed as a whole at no charge to all third
    101     parties under the terms of this License.
    102 
    103     c) If the modified program normally reads commands interactively
    104     when run, you must cause it, when started running for such
    105     interactive use in the most ordinary way, to print or display an
    106     announcement including an appropriate copyright notice and a
    107     notice that there is no warranty (or else, saying that you provide
    108     a warranty) and that users may redistribute the program under
    109     these conditions, and telling the user how to view a copy of this
    110     License.  (Exception: if the Program itself is interactive but
    111     does not normally print such an announcement, your work based on
    112     the Program is not required to print an announcement.)
    113 
    114 These requirements apply to the modified work as a whole.  If
    115 identifiable sections of that work are not derived from the Program,
    116 and can be reasonably considered independent and separate works in
    117 themselves, then this License, and its terms, do not apply to those
    118 sections when you distribute them as separate works.  But when you
    119 distribute the same sections as part of a whole which is a work based
    120 on the Program, the distribution of the whole must be on the terms of
    121 this License, whose permissions for other licensees extend to the
    122 entire whole, and thus to each and every part regardless of who wrote it.
    123 
    124 Thus, it is not the intent of this section to claim rights or contest
    125 your rights to work written entirely by you; rather, the intent is to
    126 exercise the right to control the distribution of derivative or
    127 collective works based on the Program.
    128 
    129 In addition, mere aggregation of another work not based on the Program
    130 with the Program (or with a work based on the Program) on a volume of
    131 a storage or distribution medium does not bring the other work under
    132 the scope of this License.
    133 
    134   3. You may copy and distribute the Program (or a work based on it,
    135 under Section 2) in object code or executable form under the terms of
    136 Sections 1 and 2 above provided that you also do one of the following:
    137 
    138     a) Accompany it with the complete corresponding machine-readable
    139     source code, which must be distributed under the terms of Sections
    140     1 and 2 above on a medium customarily used for software interchange; or,
    141 
    142     b) Accompany it with a written offer, valid for at least three
    143     years, to give any third party, for a charge no more than your
    144     cost of physically performing source distribution, a complete
    145     machine-readable copy of the corresponding source code, to be
    146     distributed under the terms of Sections 1 and 2 above on a medium
    147     customarily used for software interchange; or,
    148 
    149     c) Accompany it with the information you received as to the offer
    150     to distribute corresponding source code.  (This alternative is
    151     allowed only for noncommercial distribution and only if you
    152     received the program in object code or executable form with such
    153     an offer, in accord with Subsection b above.)
    154 
    155 The source code for a work means the preferred form of the work for
    156 making modifications to it.  For an executable work, complete source
    157 code means all the source code for all modules it contains, plus any
    158 associated interface definition files, plus the scripts used to
    159 control compilation and installation of the executable.  However, as a
    160 special exception, the source code distributed need not include
    161 anything that is normally distributed (in either source or binary
    162 form) with the major components (compiler, kernel, and so on) of the
    163 operating system on which the executable runs, unless that component
    164 itself accompanies the executable.
    165 
    166 If distribution of executable or object code is made by offering
    167 access to copy from a designated place, then offering equivalent
    168 access to copy the source code from the same place counts as
    169 distribution of the source code, even though third parties are not
    170 compelled to copy the source along with the object code.
    171 
    172   4. You may not copy, modify, sublicense, or distribute the Program
    173 except as expressly provided under this License.  Any attempt
    174 otherwise to copy, modify, sublicense or distribute the Program is
    175 void, and will automatically terminate your rights under this License.
    176 However, parties who have received copies, or rights, from you under
    177 this License will not have their licenses terminated so long as such
    178 parties remain in full compliance.
    179 
    180   5. You are not required to accept this License, since you have not
    181 signed it.  However, nothing else grants you permission to modify or
    182 distribute the Program or its derivative works.  These actions are
    183 prohibited by law if you do not accept this License.  Therefore, by
    184 modifying or distributing the Program (or any work based on the
    185 Program), you indicate your acceptance of this License to do so, and
    186 all its terms and conditions for copying, distributing or modifying
    187 the Program or works based on it.
    188 
    189   6. Each time you redistribute the Program (or any work based on the
    190 Program), the recipient automatically receives a license from the
    191 original licensor to copy, distribute or modify the Program subject to
    192 these terms and conditions.  You may not impose any further
    193 restrictions on the recipients' exercise of the rights granted herein.
    194 You are not responsible for enforcing compliance by third parties to
    195 this License.
    196 
    197   7. If, as a consequence of a court judgment or allegation of patent
    198 infringement or for any other reason (not limited to patent issues),
    199 conditions are imposed on you (whether by court order, agreement or
    200 otherwise) that contradict the conditions of this License, they do not
    201 excuse you from the conditions of this License.  If you cannot
    202 distribute so as to satisfy simultaneously your obligations under this
    203 License and any other pertinent obligations, then as a consequence you
    204 may not distribute the Program at all.  For example, if a patent
    205 license would not permit royalty-free redistribution of the Program by
    206 all those who receive copies directly or indirectly through you, then
    207 the only way you could satisfy both it and this License would be to
    208 refrain entirely from distribution of the Program.
    209 
    210 If any portion of this section is held invalid or unenforceable under
    211 any particular circumstance, the balance of the section is intended to
    212 apply and the section as a whole is intended to apply in other
    213 circumstances.
    214 
    215 It is not the purpose of this section to induce you to infringe any
    216 patents or other property right claims or to contest validity of any
    217 such claims; this section has the sole purpose of protecting the
    218 integrity of the free software distribution system, which is
    219 implemented by public license practices.  Many people have made
    220 generous contributions to the wide range of software distributed
    221 through that system in reliance on consistent application of that
    222 system; it is up to the author/donor to decide if he or she is willing
    223 to distribute software through any other system and a licensee cannot
    224 impose that choice.
    225 
    226 This section is intended to make thoroughly clear what is believed to
    227 be a consequence of the rest of this License.
    228 
    229   8. If the distribution and/or use of the Program is restricted in
    230 certain countries either by patents or by copyrighted interfaces, the
    231 original copyright holder who places the Program under this License
    232 may add an explicit geographical distribution limitation excluding
    233 those countries, so that distribution is permitted only in or among
    234 countries not thus excluded.  In such case, this License incorporates
    235 the limitation as if written in the body of this License.
    236 
    237   9. The Free Software Foundation may publish revised and/or new versions
    238 of the General Public License from time to time.  Such new versions will
    239 be similar in spirit to the present version, but may differ in detail to
    240 address new problems or concerns.
    241 
    242 Each version is given a distinguishing version number.  If the Program
    243 specifies a version number of this License which applies to it and "any
    244 later version", you have the option of following the terms and conditions
    245 either of that version or of any later version published by the Free
    246 Software Foundation.  If the Program does not specify a version number of
    247 this License, you may choose any version ever published by the Free Software
    248 Foundation.
    249 
    250   10. If you wish to incorporate parts of the Program into other free
    251 programs whose distribution conditions are different, write to the author
    252 to ask for permission.  For software which is copyrighted by the Free
    253 Software Foundation, write to the Free Software Foundation; we sometimes
    254 make exceptions for this.  Our decision will be guided by the two goals
    255 of preserving the free status of all derivatives of our free software and
    256 of promoting the sharing and reuse of software generally.
    257 
    258 			    NO WARRANTY
    259 
    260   11. BECAUSE THE PROGRAM IS LICENSED FREE OF CHARGE, THERE IS NO WARRANTY
    261 FOR THE PROGRAM, TO THE EXTENT PERMITTED BY APPLICABLE LAW.  EXCEPT WHEN
    262 OTHERWISE STATED IN WRITING THE COPYRIGHT HOLDERS AND/OR OTHER PARTIES
    263 PROVIDE THE PROGRAM "AS IS" WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESSED
    264 OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
    265 MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.  THE ENTIRE RISK AS
    266 TO THE QUALITY AND PERFORMANCE OF THE PROGRAM IS WITH YOU.  SHOULD THE
    267 PROGRAM PROVE DEFECTIVE, YOU ASSUME THE COST OF ALL NECESSARY SERVICING,
    268 REPAIR OR CORRECTION.
    269 
    270   12. IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING
    271 WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MAY MODIFY AND/OR
    272 REDISTRIBUTE THE PROGRAM AS PERMITTED ABOVE, BE LIABLE TO YOU FOR DAMAGES,
    273 INCLUDING ANY GENERAL, SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING
    274 OUT OF THE USE OR INABILITY TO USE THE PROGRAM (INCLUDING BUT NOT LIMITED
    275 TO LOSS OF DATA OR DATA BEING RENDERED INACCURATE OR LOSSES SUSTAINED BY
    276 YOU OR THIRD PARTIES OR A FAILURE OF THE PROGRAM TO OPERATE WITH ANY OTHER
    277 PROGRAMS), EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE
    278 POSSIBILITY OF SUCH DAMAGES.
    279 
    280 		     END OF TERMS AND CONDITIONS
    281 
    282 	    How to Apply These Terms to Your New Programs
    283 
    284   If you develop a new program, and you want it to be of the greatest
    285 possible use to the public, the best way to achieve this is to make it
    286 free software which everyone can redistribute and change under these terms.
    287 
    288   To do so, attach the following notices to the program.  It is safest
    289 to attach them to the start of each source file to most effectively
    290 convey the exclusion of warranty; and each file should have at least
    291 the "copyright" line and a pointer to where the full notice is found.
    292 
    293     <one line to give the program's name and a brief idea of what it does.>
    294     Copyright (C) <year>  <name of author>
    295 
    296     This program is free software; you can redistribute it and/or modify
    297     it under the terms of the GNU General Public License as published by
    298     the Free Software Foundation; either version 2 of the License, or
    299     (at your option) any later version.
    300 
    301     This program is distributed in the hope that it will be useful,
    302     but WITHOUT ANY WARRANTY; without even the implied warranty of
    303     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    304     GNU General Public License for more details.
    305 
    306     You should have received a copy of the GNU General Public License
    307     along with this program; if not, write to the Free Software
    308     Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
    309 
    310 
    311 Also add information on how to contact you by electronic and paper mail.
    312 
    313 If the program is interactive, make it output a short notice like this
    314 when it starts in an interactive mode:
    315 
    316     Gnomovision version 69, Copyright (C) year  name of author
    317     Gnomovision comes with ABSOLUTELY NO WARRANTY; for details type `show w'.
    318     This is free software, and you are welcome to redistribute it
    319     under certain conditions; type `show c' for details.
    320 
    321 The hypothetical commands `show w' and `show c' should show the appropriate
    322 parts of the General Public License.  Of course, the commands you use may
    323 be called something other than `show w' and `show c'; they could even be
    324 mouse-clicks or menu items--whatever suits your program.
    325 
    326 You should also get your employer (if you work as a programmer) or your
    327 school, if any, to sign a "copyright disclaimer" for the program, if
    328 necessary.  Here is a sample; alter the names:
    329 
    330   Yoyodyne, Inc., hereby disclaims all copyright interest in the program
    331   `Gnomovision' (which makes passes at compilers) written by James Hacker.
    332 
    333   <signature of Ty Coon>, 1 April 1989
    334   Ty Coon, President of Vice
    335 
    336 This General Public License does not permit incorporating your program into
    337 proprietary programs.  If your program is a subroutine library, you may
    338 consider it more useful to permit linking proprietary applications with the
    339 library.  If this is what you want to do, use the GNU Library General
    340 Public License instead of this License.
    341