contrib / subtree / COPYINGon commit Merge branch 'jx/clean-interactive' (9b4aa47)
   1                    GNU GENERAL PUBLIC LICENSE
   2                       Version 2, June 1991
   3
   4 Copyright (C) 1989, 1991 Free Software Foundation, Inc.,
   5 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 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
  12freedom to share and change it.  By contrast, the GNU General Public
  13License is intended to guarantee your freedom to share and change free
  14software--to make sure the software is free for all its users.  This
  15General Public License applies to most of the Free Software
  16Foundation's software and to any other program whose authors commit to
  17using it.  (Some other Free Software Foundation software is covered by
  18the GNU Lesser General Public License instead.)  You can apply it to
  19your programs, too.
  20
  21  When we speak of free software, we are referring to freedom, not
  22price.  Our General Public Licenses are designed to make sure that you
  23have the freedom to distribute copies of free software (and charge for
  24this service if you wish), that you receive source code or can get it
  25if you want it, that you can change the software or use pieces of it
  26in 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
  29anyone to deny you these rights or to ask you to surrender the rights.
  30These restrictions translate to certain responsibilities for you if you
  31distribute copies of the software, or if you modify it.
  32
  33  For example, if you distribute copies of such a program, whether
  34gratis or for a fee, you must give the recipients all the rights that
  35you have.  You must make sure that they, too, receive or can get the
  36source code.  And you must show them these terms so they know their
  37rights.
  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,
  41distribute and/or modify the software.
  42
  43  Also, for each author's protection and ours, we want to make certain
  44that everyone understands that there is no warranty for this free
  45software.  If the software is modified by someone else and passed on, we
  46want its recipients to know that what they have is not the original, so
  47that any problems introduced by others will not reflect on the original
  48authors' reputations.
  49
  50  Finally, any free program is threatened constantly by software
  51patents.  We wish to avoid the danger that redistributors of a free
  52program will individually obtain patent licenses, in effect making the
  53program proprietary.  To prevent this, we have made it clear that any
  54patent must be licensed for everyone's free use or not licensed at all.
  55
  56  The precise terms and conditions for copying, distribution and
  57modification 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
  63a notice placed by the copyright holder saying it may be distributed
  64under the terms of this General Public License.  The "Program", below,
  65refers to any such program or work, and a "work based on the Program"
  66means either the Program or any derivative work under copyright law:
  67that is to say, a work containing the Program or a portion of it,
  68either verbatim or with modifications and/or translated into another
  69language.  (Hereinafter, translation is included without limitation in
  70the term "modification".)  Each licensee is addressed as "you".
  71
  72Activities other than copying, distribution and modification are not
  73covered by this License; they are outside its scope.  The act of
  74running the Program is not restricted, and the output from the Program
  75is covered only if its contents constitute a work based on the
  76Program (independent of having been made by running the Program).
  77Whether that is true depends on what the Program does.
  78
  79  1. You may copy and distribute verbatim copies of the Program's
  80source code as you receive it, in any medium, provided that you
  81conspicuously and appropriately publish on each copy an appropriate
  82copyright notice and disclaimer of warranty; keep intact all the
  83notices that refer to this License and to the absence of any warranty;
  84and give any other recipients of the Program a copy of this License
  85along with the Program.
  86
  87You may charge a fee for the physical act of transferring a copy, and
  88you 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
  91of it, thus forming a work based on the Program, and copy and
  92distribute such modifications or work under the terms of Section 1
  93above, 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
 114These requirements apply to the modified work as a whole.  If
 115identifiable sections of that work are not derived from the Program,
 116and can be reasonably considered independent and separate works in
 117themselves, then this License, and its terms, do not apply to those
 118sections when you distribute them as separate works.  But when you
 119distribute the same sections as part of a whole which is a work based
 120on the Program, the distribution of the whole must be on the terms of
 121this License, whose permissions for other licensees extend to the
 122entire whole, and thus to each and every part regardless of who wrote it.
 123
 124Thus, it is not the intent of this section to claim rights or contest
 125your rights to work written entirely by you; rather, the intent is to
 126exercise the right to control the distribution of derivative or
 127collective works based on the Program.
 128
 129In addition, mere aggregation of another work not based on the Program
 130with the Program (or with a work based on the Program) on a volume of
 131a storage or distribution medium does not bring the other work under
 132the scope of this License.
 133
 134  3. You may copy and distribute the Program (or a work based on it,
 135under Section 2) in object code or executable form under the terms of
 136Sections 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
 155The source code for a work means the preferred form of the work for
 156making modifications to it.  For an executable work, complete source
 157code means all the source code for all modules it contains, plus any
 158associated interface definition files, plus the scripts used to
 159control compilation and installation of the executable.  However, as a
 160special exception, the source code distributed need not include
 161anything that is normally distributed (in either source or binary
 162form) with the major components (compiler, kernel, and so on) of the
 163operating system on which the executable runs, unless that component
 164itself accompanies the executable.
 165
 166If distribution of executable or object code is made by offering
 167access to copy from a designated place, then offering equivalent
 168access to copy the source code from the same place counts as
 169distribution of the source code, even though third parties are not
 170compelled to copy the source along with the object code.
 171
 172  4. You may not copy, modify, sublicense, or distribute the Program
 173except as expressly provided under this License.  Any attempt
 174otherwise to copy, modify, sublicense or distribute the Program is
 175void, and will automatically terminate your rights under this License.
 176However, parties who have received copies, or rights, from you under
 177this License will not have their licenses terminated so long as such
 178parties remain in full compliance.
 179
 180  5. You are not required to accept this License, since you have not
 181signed it.  However, nothing else grants you permission to modify or
 182distribute the Program or its derivative works.  These actions are
 183prohibited by law if you do not accept this License.  Therefore, by
 184modifying or distributing the Program (or any work based on the
 185Program), you indicate your acceptance of this License to do so, and
 186all its terms and conditions for copying, distributing or modifying
 187the Program or works based on it.
 188
 189  6. Each time you redistribute the Program (or any work based on the
 190Program), the recipient automatically receives a license from the
 191original licensor to copy, distribute or modify the Program subject to
 192these terms and conditions.  You may not impose any further
 193restrictions on the recipients' exercise of the rights granted herein.
 194You are not responsible for enforcing compliance by third parties to
 195this License.
 196
 197  7. If, as a consequence of a court judgment or allegation of patent
 198infringement or for any other reason (not limited to patent issues),
 199conditions are imposed on you (whether by court order, agreement or
 200otherwise) that contradict the conditions of this License, they do not
 201excuse you from the conditions of this License.  If you cannot
 202distribute so as to satisfy simultaneously your obligations under this
 203License and any other pertinent obligations, then as a consequence you
 204may not distribute the Program at all.  For example, if a patent
 205license would not permit royalty-free redistribution of the Program by
 206all those who receive copies directly or indirectly through you, then
 207the only way you could satisfy both it and this License would be to
 208refrain entirely from distribution of the Program.
 209
 210If any portion of this section is held invalid or unenforceable under
 211any particular circumstance, the balance of the section is intended to
 212apply and the section as a whole is intended to apply in other
 213circumstances.
 214
 215It is not the purpose of this section to induce you to infringe any
 216patents or other property right claims or to contest validity of any
 217such claims; this section has the sole purpose of protecting the
 218integrity of the free software distribution system, which is
 219implemented by public license practices.  Many people have made
 220generous contributions to the wide range of software distributed
 221through that system in reliance on consistent application of that
 222system; it is up to the author/donor to decide if he or she is willing
 223to distribute software through any other system and a licensee cannot
 224impose that choice.
 225
 226This section is intended to make thoroughly clear what is believed to
 227be a consequence of the rest of this License.
 228
 229  8. If the distribution and/or use of the Program is restricted in
 230certain countries either by patents or by copyrighted interfaces, the
 231original copyright holder who places the Program under this License
 232may add an explicit geographical distribution limitation excluding
 233those countries, so that distribution is permitted only in or among
 234countries not thus excluded.  In such case, this License incorporates
 235the limitation as if written in the body of this License.
 236
 237  9. The Free Software Foundation may publish revised and/or new versions
 238of the General Public License from time to time.  Such new versions will
 239be similar in spirit to the present version, but may differ in detail to
 240address new problems or concerns.
 241
 242Each version is given a distinguishing version number.  If the Program
 243specifies a version number of this License which applies to it and "any
 244later version", you have the option of following the terms and conditions
 245either of that version or of any later version published by the Free
 246Software Foundation.  If the Program does not specify a version number of
 247this License, you may choose any version ever published by the Free Software
 248Foundation.
 249
 250  10. If you wish to incorporate parts of the Program into other free
 251programs whose distribution conditions are different, write to the author
 252to ask for permission.  For software which is copyrighted by the Free
 253Software Foundation, write to the Free Software Foundation; we sometimes
 254make exceptions for this.  Our decision will be guided by the two goals
 255of preserving the free status of all derivatives of our free software and
 256of 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
 261FOR THE PROGRAM, TO THE EXTENT PERMITTED BY APPLICABLE LAW.  EXCEPT WHEN
 262OTHERWISE STATED IN WRITING THE COPYRIGHT HOLDERS AND/OR OTHER PARTIES
 263PROVIDE THE PROGRAM "AS IS" WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESSED
 264OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
 265MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.  THE ENTIRE RISK AS
 266TO THE QUALITY AND PERFORMANCE OF THE PROGRAM IS WITH YOU.  SHOULD THE
 267PROGRAM PROVE DEFECTIVE, YOU ASSUME THE COST OF ALL NECESSARY SERVICING,
 268REPAIR OR CORRECTION.
 269
 270  12. IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING
 271WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MAY MODIFY AND/OR
 272REDISTRIBUTE THE PROGRAM AS PERMITTED ABOVE, BE LIABLE TO YOU FOR DAMAGES,
 273INCLUDING ANY GENERAL, SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING
 274OUT OF THE USE OR INABILITY TO USE THE PROGRAM (INCLUDING BUT NOT LIMITED
 275TO LOSS OF DATA OR DATA BEING RENDERED INACCURATE OR LOSSES SUSTAINED BY
 276YOU OR THIRD PARTIES OR A FAILURE OF THE PROGRAM TO OPERATE WITH ANY OTHER
 277PROGRAMS), EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE
 278POSSIBILITY 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
 285possible use to the public, the best way to achieve this is to make it
 286free 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
 289to attach them to the start of each source file to most effectively
 290convey the exclusion of warranty; and each file should have at least
 291the "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 along
 307    with this program; if not, write to the Free Software Foundation, Inc.,
 308    51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 309
 310Also add information on how to contact you by electronic and paper mail.
 311
 312If the program is interactive, make it output a short notice like this
 313when it starts in an interactive mode:
 314
 315    Gnomovision version 69, Copyright (C) year name of author
 316    Gnomovision comes with ABSOLUTELY NO WARRANTY; for details type `show w'.
 317    This is free software, and you are welcome to redistribute it
 318    under certain conditions; type `show c' for details.
 319
 320The hypothetical commands `show w' and `show c' should show the appropriate
 321parts of the General Public License.  Of course, the commands you use may
 322be called something other than `show w' and `show c'; they could even be
 323mouse-clicks or menu items--whatever suits your program.
 324
 325You should also get your employer (if you work as a programmer) or your
 326school, if any, to sign a "copyright disclaimer" for the program, if
 327necessary.  Here is a sample; alter the names:
 328
 329  Yoyodyne, Inc., hereby disclaims all copyright interest in the program
 330  `Gnomovision' (which makes passes at compilers) written by James Hacker.
 331
 332  <signature of Ty Coon>, 1 April 1989
 333  Ty Coon, President of Vice
 334
 335This General Public License does not permit incorporating your program into
 336proprietary programs.  If your program is a subroutine library, you may
 337consider it more useful to permit linking proprietary applications with the
 338library.  If this is what you want to do, use the GNU Lesser General
 339Public License instead of this License.