1@ignore
2@c Set file name and title for man page.
3@setfilename gpl
4@settitle GNU General Public License
5@c man begin SEEALSO
6gfdl(7), fsf-funding(7).
7@c man end
8@c man begin COPYRIGHT
9Copyright @copyright{} 1989, 1991 Free Software Foundation, Inc.
1051 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
11
12Everyone is permitted to copy and distribute verbatim copies
13of this license document, but changing it is not allowed.
14@c man end
15@end ignore
16@node Copying
17@c man begin DESCRIPTION
18@unnumbered GNU GENERAL PUBLIC LICENSE
19@center Version 2, June 1991
20
21@c This file is intended to be included in another file.
22
23@display
24Copyright @copyright{} 1989, 1991 Free Software Foundation, Inc.
2551 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
26
27Everyone is permitted to copy and distribute verbatim copies
28of this license document, but changing it is not allowed.
29@end display
30
31@unnumberedsec Preamble
32
33  The licenses for most software are designed to take away your
34freedom to share and change it.  By contrast, the GNU General Public
35License is intended to guarantee your freedom to share and change free
36software---to make sure the software is free for all its users.  This
37General Public License applies to most of the Free Software
38Foundation's software and to any other program whose authors commit to
39using it.  (Some other Free Software Foundation software is covered by
40the GNU Library General Public License instead.)  You can apply it to
41your programs, too.
42
43  When we speak of free software, we are referring to freedom, not
44price.  Our General Public Licenses are designed to make sure that you
45have the freedom to distribute copies of free software (and charge for
46this service if you wish), that you receive source code or can get it
47if you want it, that you can change the software or use pieces of it
48in new free programs; and that you know you can do these things.
49
50  To protect your rights, we need to make restrictions that forbid
51anyone to deny you these rights or to ask you to surrender the rights.
52These restrictions translate to certain responsibilities for you if you
53distribute copies of the software, or if you modify it.
54
55  For example, if you distribute copies of such a program, whether
56gratis or for a fee, you must give the recipients all the rights that
57you have.  You must make sure that they, too, receive or can get the
58source code.  And you must show them these terms so they know their
59rights.
60
61  We protect your rights with two steps: (1) copyright the software, and
62(2) offer you this license which gives you legal permission to copy,
63distribute and/or modify the software.
64
65  Also, for each author's protection and ours, we want to make certain
66that everyone understands that there is no warranty for this free
67software.  If the software is modified by someone else and passed on, we
68want its recipients to know that what they have is not the original, so
69that any problems introduced by others will not reflect on the original
70authors' reputations.
71
72  Finally, any free program is threatened constantly by software
73patents.  We wish to avoid the danger that redistributors of a free
74program will individually obtain patent licenses, in effect making the
75program proprietary.  To prevent this, we have made it clear that any
76patent must be licensed for everyone's free use or not licensed at all.
77
78  The precise terms and conditions for copying, distribution and
79modification follow.
80
81@iftex
82@unnumberedsec TERMS AND CONDITIONS FOR COPYING, DISTRIBUTION AND MODIFICATION
83@end iftex
84@ifnottex
85@center TERMS AND CONDITIONS FOR COPYING, DISTRIBUTION AND MODIFICATION
86@end ifnottex
87
88@enumerate 0
89@item
90This License applies to any program or other work which contains
91a notice placed by the copyright holder saying it may be distributed
92under the terms of this General Public License.  The ``Program'', below,
93refers to any such program or work, and a ``work based on the Program''
94means either the Program or any derivative work under copyright law:
95that is to say, a work containing the Program or a portion of it,
96either verbatim or with modifications and/or translated into another
97language.  (Hereinafter, translation is included without limitation in
98the term ``modification''.)  Each licensee is addressed as ``you''.
99
100Activities other than copying, distribution and modification are not
101covered by this License; they are outside its scope.  The act of
102running the Program is not restricted, and the output from the Program
103is covered only if its contents constitute a work based on the
104Program (independent of having been made by running the Program).
105Whether that is true depends on what the Program does.
106
107@item
108You may copy and distribute verbatim copies of the Program's
109source code as you receive it, in any medium, provided that you
110conspicuously and appropriately publish on each copy an appropriate
111copyright notice and disclaimer of warranty; keep intact all the
112notices that refer to this License and to the absence of any warranty;
113and give any other recipients of the Program a copy of this License
114along with the Program.
115
116You may charge a fee for the physical act of transferring a copy, and
117you may at your option offer warranty protection in exchange for a fee.
118
119@item
120You may modify your copy or copies of the Program or any portion
121of it, thus forming a work based on the Program, and copy and
122distribute such modifications or work under the terms of Section 1
123above, provided that you also meet all of these conditions:
124
125@enumerate a
126@item
127You must cause the modified files to carry prominent notices
128stating that you changed the files and the date of any change.
129
130@item
131You must cause any work that you distribute or publish, that in
132whole or in part contains or is derived from the Program or any
133part thereof, to be licensed as a whole at no charge to all third
134parties under the terms of this License.
135
136@item
137If the modified program normally reads commands interactively
138when run, you must cause it, when started running for such
139interactive use in the most ordinary way, to print or display an
140announcement including an appropriate copyright notice and a
141notice that there is no warranty (or else, saying that you provide
142a warranty) and that users may redistribute the program under
143these conditions, and telling the user how to view a copy of this
144License.  (Exception: if the Program itself is interactive but
145does not normally print such an announcement, your work based on
146the Program is not required to print an announcement.)
147@end enumerate
148
149These requirements apply to the modified work as a whole.  If
150identifiable sections of that work are not derived from the Program,
151and can be reasonably considered independent and separate works in
152themselves, then this License, and its terms, do not apply to those
153sections when you distribute them as separate works.  But when you
154distribute the same sections as part of a whole which is a work based
155on the Program, the distribution of the whole must be on the terms of
156this License, whose permissions for other licensees extend to the
157entire whole, and thus to each and every part regardless of who wrote it.
158
159Thus, it is not the intent of this section to claim rights or contest
160your rights to work written entirely by you; rather, the intent is to
161exercise the right to control the distribution of derivative or
162collective works based on the Program.
163
164In addition, mere aggregation of another work not based on the Program
165with the Program (or with a work based on the Program) on a volume of
166a storage or distribution medium does not bring the other work under
167the scope of this License.
168
169@item
170You may copy and distribute the Program (or a work based on it,
171under Section 2) in object code or executable form under the terms of
172Sections 1 and 2 above provided that you also do one of the following:
173
174@enumerate a
175@item
176Accompany it with the complete corresponding machine-readable
177source code, which must be distributed under the terms of Sections
1781 and 2 above on a medium customarily used for software interchange; or,
179
180@item
181Accompany it with a written offer, valid for at least three
182years, to give any third party, for a charge no more than your
183cost of physically performing source distribution, a complete
184machine-readable copy of the corresponding source code, to be
185distributed under the terms of Sections 1 and 2 above on a medium
186customarily used for software interchange; or,
187
188@item
189Accompany it with the information you received as to the offer
190to distribute corresponding source code.  (This alternative is
191allowed only for noncommercial distribution and only if you
192received the program in object code or executable form with such
193an offer, in accord with Subsection b above.)
194@end enumerate
195
196The source code for a work means the preferred form of the work for
197making modifications to it.  For an executable work, complete source
198code means all the source code for all modules it contains, plus any
199associated interface definition files, plus the scripts used to
200control compilation and installation of the executable.  However, as a
201special exception, the source code distributed need not include
202anything that is normally distributed (in either source or binary
203form) with the major components (compiler, kernel, and so on) of the
204operating system on which the executable runs, unless that component
205itself accompanies the executable.
206
207If distribution of executable or object code is made by offering
208access to copy from a designated place, then offering equivalent
209access to copy the source code from the same place counts as
210distribution of the source code, even though third parties are not
211compelled to copy the source along with the object code.
212
213@item
214You may not copy, modify, sublicense, or distribute the Program
215except as expressly provided under this License.  Any attempt
216otherwise to copy, modify, sublicense or distribute the Program is
217void, and will automatically terminate your rights under this License.
218However, parties who have received copies, or rights, from you under
219this License will not have their licenses terminated so long as such
220parties remain in full compliance.
221
222@item
223You are not required to accept this License, since you have not
224signed it.  However, nothing else grants you permission to modify or
225distribute the Program or its derivative works.  These actions are
226prohibited by law if you do not accept this License.  Therefore, by
227modifying or distributing the Program (or any work based on the
228Program), you indicate your acceptance of this License to do so, and
229all its terms and conditions for copying, distributing or modifying
230the Program or works based on it.
231
232@item
233Each time you redistribute the Program (or any work based on the
234Program), the recipient automatically receives a license from the
235original licensor to copy, distribute or modify the Program subject to
236these terms and conditions.  You may not impose any further
237restrictions on the recipients' exercise of the rights granted herein.
238You are not responsible for enforcing compliance by third parties to
239this License.
240
241@item
242If, as a consequence of a court judgment or allegation of patent
243infringement or for any other reason (not limited to patent issues),
244conditions are imposed on you (whether by court order, agreement or
245otherwise) that contradict the conditions of this License, they do not
246excuse you from the conditions of this License.  If you cannot
247distribute so as to satisfy simultaneously your obligations under this
248License and any other pertinent obligations, then as a consequence you
249may not distribute the Program at all.  For example, if a patent
250license would not permit royalty-free redistribution of the Program by
251all those who receive copies directly or indirectly through you, then
252the only way you could satisfy both it and this License would be to
253refrain entirely from distribution of the Program.
254
255If any portion of this section is held invalid or unenforceable under
256any particular circumstance, the balance of the section is intended to
257apply and the section as a whole is intended to apply in other
258circumstances.
259
260It is not the purpose of this section to induce you to infringe any
261patents or other property right claims or to contest validity of any
262such claims; this section has the sole purpose of protecting the
263integrity of the free software distribution system, which is
264implemented by public license practices.  Many people have made
265generous contributions to the wide range of software distributed
266through that system in reliance on consistent application of that
267system; it is up to the author/donor to decide if he or she is willing
268to distribute software through any other system and a licensee cannot
269impose that choice.
270
271This section is intended to make thoroughly clear what is believed to
272be a consequence of the rest of this License.
273
274@item
275If the distribution and/or use of the Program is restricted in
276certain countries either by patents or by copyrighted interfaces, the
277original copyright holder who places the Program under this License
278may add an explicit geographical distribution limitation excluding
279those countries, so that distribution is permitted only in or among
280countries not thus excluded.  In such case, this License incorporates
281the limitation as if written in the body of this License.
282
283@item
284The Free Software Foundation may publish revised and/or new versions
285of the General Public License from time to time.  Such new versions will
286be similar in spirit to the present version, but may differ in detail to
287address new problems or concerns.
288
289Each version is given a distinguishing version number.  If the Program
290specifies a version number of this License which applies to it and ``any
291later version'', you have the option of following the terms and conditions
292either of that version or of any later version published by the Free
293Software Foundation.  If the Program does not specify a version number of
294this License, you may choose any version ever published by the Free Software
295Foundation.
296
297@item
298If you wish to incorporate parts of the Program into other free
299programs whose distribution conditions are different, write to the author
300to ask for permission.  For software which is copyrighted by the Free
301Software Foundation, write to the Free Software Foundation; we sometimes
302make exceptions for this.  Our decision will be guided by the two goals
303of preserving the free status of all derivatives of our free software and
304of promoting the sharing and reuse of software generally.
305
306@iftex
307@heading NO WARRANTY
308@end iftex
309@ifnottex
310@center NO WARRANTY
311@end ifnottex
312
313@item
314BECAUSE THE PROGRAM IS LICENSED FREE OF CHARGE, THERE IS NO WARRANTY
315FOR THE PROGRAM, TO THE EXTENT PERMITTED BY APPLICABLE LAW.  EXCEPT WHEN
316OTHERWISE STATED IN WRITING THE COPYRIGHT HOLDERS AND/OR OTHER PARTIES
317PROVIDE THE PROGRAM ``AS IS'' WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESSED
318OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
319MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.  THE ENTIRE RISK AS
320TO THE QUALITY AND PERFORMANCE OF THE PROGRAM IS WITH YOU.  SHOULD THE
321PROGRAM PROVE DEFECTIVE, YOU ASSUME THE COST OF ALL NECESSARY SERVICING,
322REPAIR OR CORRECTION.
323
324@item
325IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING
326WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MAY MODIFY AND/OR
327REDISTRIBUTE THE PROGRAM AS PERMITTED ABOVE, BE LIABLE TO YOU FOR DAMAGES,
328INCLUDING ANY GENERAL, SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING
329OUT OF THE USE OR INABILITY TO USE THE PROGRAM (INCLUDING BUT NOT LIMITED
330TO LOSS OF DATA OR DATA BEING RENDERED INACCURATE OR LOSSES SUSTAINED BY
331YOU OR THIRD PARTIES OR A FAILURE OF THE PROGRAM TO OPERATE WITH ANY OTHER
332PROGRAMS), EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE
333POSSIBILITY OF SUCH DAMAGES.
334@end enumerate
335
336@iftex
337@heading END OF TERMS AND CONDITIONS
338@end iftex
339@ifnottex
340@center END OF TERMS AND CONDITIONS
341@end ifnottex
342
343@page
344@unnumberedsec Appendix: How to Apply These Terms to Your New Programs
345
346  If you develop a new program, and you want it to be of the greatest
347possible use to the public, the best way to achieve this is to make it
348free software which everyone can redistribute and change under these terms.
349
350  To do so, attach the following notices to the program.  It is safest
351to attach them to the start of each source file to most effectively
352convey the exclusion of warranty; and each file should have at least
353the ``copyright'' line and a pointer to where the full notice is found.
354
355@smallexample
356@var{one line to give the program's name and a brief idea of what it does.}
357Copyright (C) @var{year}  @var{name of author}
358
359This program is free software; you can redistribute it and/or modify
360it under the terms of the GNU General Public License as published by
361the Free Software Foundation; either version 2 of the License, or
362(at your option) any later version.
363
364This program is distributed in the hope that it will be useful,
365but WITHOUT ANY WARRANTY; without even the implied warranty of
366MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
367GNU General Public License for more details.
368
369You should have received a copy of the GNU General Public License
370along with this program; if not, write to the Free Software
371Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
372@end smallexample
373
374Also add information on how to contact you by electronic and paper mail.
375
376If the program is interactive, make it output a short notice like this
377when it starts in an interactive mode:
378
379@smallexample
380Gnomovision version 69, Copyright (C) @var{year} @var{name of author}
381Gnomovision comes with ABSOLUTELY NO WARRANTY; for details
382type `show w'.
383This is free software, and you are welcome to redistribute it
384under certain conditions; type `show c' for details.
385@end smallexample
386
387The hypothetical commands @samp{show w} and @samp{show c} should show
388the appropriate parts of the General Public License.  Of course, the
389commands you use may be called something other than @samp{show w} and
390@samp{show c}; they could even be mouse-clicks or menu items---whatever
391suits your program.
392
393You should also get your employer (if you work as a programmer) or your
394school, if any, to sign a ``copyright disclaimer'' for the program, if
395necessary.  Here is a sample; alter the names:
396
397@example
398Yoyodyne, Inc., hereby disclaims all copyright interest in the program
399`Gnomovision' (which makes passes at compilers) written by James Hacker.
400
401@var{signature of Ty Coon}, 1 April 1989
402Ty Coon, President of Vice
403@end example
404
405This General Public License does not permit incorporating your program into
406proprietary programs.  If your program is a subroutine library, you may
407consider it more useful to permit linking proprietary applications with the
408library.  If this is what you want to do, use the GNU Library General
409Public License instead of this License.
410@c man end
411