1@node GNU GPL
2@appendixsec GNU GENERAL PUBLIC LICENSE
3@cindex GPL, GNU General Public License
4@cindex License, GNU GPL
5@center Version 2, June 1991
6
7@c This file is intended to be included in another file.
8
9@display
10Copyright @copyright{} 1989, 1991 Free Software Foundation, Inc.
1151 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
12
13Everyone is permitted to copy and distribute verbatim copies
14of this license document, but changing it is not allowed.
15@end display
16
17@unnumberedsubsec Preamble
18
19  The licenses for most software are designed to take away your
20freedom to share and change it.  By contrast, the GNU General Public
21License is intended to guarantee your freedom to share and change free
22software---to make sure the software is free for all its users.  This
23General Public License applies to most of the Free Software
24Foundation's software and to any other program whose authors commit to
25using it.  (Some other Free Software Foundation software is covered by
26the GNU Library General Public License instead.)  You can apply it to
27your programs, too.
28
29  When we speak of free software, we are referring to freedom, not
30price.  Our General Public Licenses are designed to make sure that you
31have the freedom to distribute copies of free software (and charge for
32this service if you wish), that you receive source code or can get it
33if you want it, that you can change the software or use pieces of it
34in new free programs; and that you know you can do these things.
35
36  To protect your rights, we need to make restrictions that forbid
37anyone to deny you these rights or to ask you to surrender the rights.
38These restrictions translate to certain responsibilities for you if you
39distribute copies of the software, or if you modify it.
40
41  For example, if you distribute copies of such a program, whether
42gratis or for a fee, you must give the recipients all the rights that
43you have.  You must make sure that they, too, receive or can get the
44source code.  And you must show them these terms so they know their
45rights.
46
47  We protect your rights with two steps: (1) copyright the software, and
48(2) offer you this license which gives you legal permission to copy,
49distribute and/or modify the software.
50
51  Also, for each author's protection and ours, we want to make certain
52that everyone understands that there is no warranty for this free
53software.  If the software is modified by someone else and passed on, we
54want its recipients to know that what they have is not the original, so
55that any problems introduced by others will not reflect on the original
56authors' reputations.
57
58  Finally, any free program is threatened constantly by software
59patents.  We wish to avoid the danger that redistributors of a free
60program will individually obtain patent licenses, in effect making the
61program proprietary.  To prevent this, we have made it clear that any
62patent must be licensed for everyone's free use or not licensed at all.
63
64  The precise terms and conditions for copying, distribution and
65modification follow.
66
67@iftex
68@unnumberedsubsec TERMS AND CONDITIONS FOR COPYING, DISTRIBUTION AND MODIFICATION
69@end iftex
70@ifinfo
71@center TERMS AND CONDITIONS FOR COPYING, DISTRIBUTION AND MODIFICATION
72
73@end ifinfo
74
75@enumerate 0
76@item
77This License applies to any program or other work which contains
78a notice placed by the copyright holder saying it may be distributed
79under the terms of this General Public License.  The ``Program'', below,
80refers to any such program or work, and a ``work based on the Program''
81means either the Program or any derivative work under copyright law:
82that is to say, a work containing the Program or a portion of it,
83either verbatim or with modifications and/or translated into another
84language.  (Hereinafter, translation is included without limitation in
85the term ``modification''.)  Each licensee is addressed as ``you''.
86
87Activities other than copying, distribution and modification are not
88covered by this License; they are outside its scope.  The act of
89running the Program is not restricted, and the output from the Program
90is covered only if its contents constitute a work based on the
91Program (independent of having been made by running the Program).
92Whether that is true depends on what the Program does.
93
94@item
95You may copy and distribute verbatim copies of the Program's
96source code as you receive it, in any medium, provided that you
97conspicuously and appropriately publish on each copy an appropriate
98copyright notice and disclaimer of warranty; keep intact all the
99notices that refer to this License and to the absence of any warranty;
100and give any other recipients of the Program a copy of this License
101along with the Program.
102
103You may charge a fee for the physical act of transferring a copy, and
104you may at your option offer warranty protection in exchange for a fee.
105
106@item
107You may modify your copy or copies of the Program or any portion
108of it, thus forming a work based on the Program, and copy and
109distribute such modifications or work under the terms of Section 1
110above, provided that you also meet all of these conditions:
111
112@enumerate a
113@item
114You must cause the modified files to carry prominent notices
115stating that you changed the files and the date of any change.
116
117@item
118You must cause any work that you distribute or publish, that in
119whole or in part contains or is derived from the Program or any
120part thereof, to be licensed as a whole at no charge to all third
121parties under the terms of this License.
122
123@item
124If the modified program normally reads commands interactively
125when run, you must cause it, when started running for such
126interactive use in the most ordinary way, to print or display an
127announcement including an appropriate copyright notice and a
128notice that there is no warranty (or else, saying that you provide
129a warranty) and that users may redistribute the program under
130these conditions, and telling the user how to view a copy of this
131License.  (Exception: if the Program itself is interactive but
132does not normally print such an announcement, your work based on
133the Program is not required to print an announcement.)
134@end enumerate
135
136These requirements apply to the modified work as a whole.  If
137identifiable sections of that work are not derived from the Program,
138and can be reasonably considered independent and separate works in
139themselves, then this License, and its terms, do not apply to those
140sections when you distribute them as separate works.  But when you
141distribute the same sections as part of a whole which is a work based
142on the Program, the distribution of the whole must be on the terms of
143this License, whose permissions for other licensees extend to the
144entire whole, and thus to each and every part regardless of who wrote it.
145
146Thus, it is not the intent of this section to claim rights or contest
147your rights to work written entirely by you; rather, the intent is to
148exercise the right to control the distribution of derivative or
149collective works based on the Program.
150
151In addition, mere aggregation of another work not based on the Program
152with the Program (or with a work based on the Program) on a volume of
153a storage or distribution medium does not bring the other work under
154the scope of this License.
155
156@item
157You may copy and distribute the Program (or a work based on it,
158under Section 2) in object code or executable form under the terms of
159Sections 1 and 2 above provided that you also do one of the following:
160
161@enumerate a
162@item
163Accompany it with the complete corresponding machine-readable
164source code, which must be distributed under the terms of Sections
1651 and 2 above on a medium customarily used for software interchange; or,
166
167@item
168Accompany it with a written offer, valid for at least three
169years, to give any third party, for a charge no more than your
170cost of physically performing source distribution, a complete
171machine-readable copy of the corresponding source code, to be
172distributed under the terms of Sections 1 and 2 above on a medium
173customarily used for software interchange; or,
174
175@item
176Accompany it with the information you received as to the offer
177to distribute corresponding source code.  (This alternative is
178allowed only for noncommercial distribution and only if you
179received the program in object code or executable form with such
180an offer, in accord with Subsection b above.)
181@end enumerate
182
183The source code for a work means the preferred form of the work for
184making modifications to it.  For an executable work, complete source
185code means all the source code for all modules it contains, plus any
186associated interface definition files, plus the scripts used to
187control compilation and installation of the executable.  However, as a
188special exception, the source code distributed need not include
189anything that is normally distributed (in either source or binary
190form) with the major components (compiler, kernel, and so on) of the
191operating system on which the executable runs, unless that component
192itself accompanies the executable.
193
194If distribution of executable or object code is made by offering
195access to copy from a designated place, then offering equivalent
196access to copy the source code from the same place counts as
197distribution of the source code, even though third parties are not
198compelled to copy the source along with the object code.
199
200@item
201You may not copy, modify, sublicense, or distribute the Program
202except as expressly provided under this License.  Any attempt
203otherwise to copy, modify, sublicense or distribute the Program is
204void, and will automatically terminate your rights under this License.
205However, parties who have received copies, or rights, from you under
206this License will not have their licenses terminated so long as such
207parties remain in full compliance.
208
209@item
210You are not required to accept this License, since you have not
211signed it.  However, nothing else grants you permission to modify or
212distribute the Program or its derivative works.  These actions are
213prohibited by law if you do not accept this License.  Therefore, by
214modifying or distributing the Program (or any work based on the
215Program), you indicate your acceptance of this License to do so, and
216all its terms and conditions for copying, distributing or modifying
217the Program or works based on it.
218
219@item
220Each time you redistribute the Program (or any work based on the
221Program), the recipient automatically receives a license from the
222original licensor to copy, distribute or modify the Program subject to
223these terms and conditions.  You may not impose any further
224restrictions on the recipients' exercise of the rights granted herein.
225You are not responsible for enforcing compliance by third parties to
226this License.
227
228@item
229If, as a consequence of a court judgment or allegation of patent
230infringement or for any other reason (not limited to patent issues),
231conditions are imposed on you (whether by court order, agreement or
232otherwise) that contradict the conditions of this License, they do not
233excuse you from the conditions of this License.  If you cannot
234distribute so as to satisfy simultaneously your obligations under this
235License and any other pertinent obligations, then as a consequence you
236may not distribute the Program at all.  For example, if a patent
237license would not permit royalty-free redistribution of the Program by
238all those who receive copies directly or indirectly through you, then
239the only way you could satisfy both it and this License would be to
240refrain entirely from distribution of the Program.
241
242If any portion of this section is held invalid or unenforceable under
243any particular circumstance, the balance of the section is intended to
244apply and the section as a whole is intended to apply in other
245circumstances.
246
247It is not the purpose of this section to induce you to infringe any
248patents or other property right claims or to contest validity of any
249such claims; this section has the sole purpose of protecting the
250integrity of the free software distribution system, which is
251implemented by public license practices.  Many people have made
252generous contributions to the wide range of software distributed
253through that system in reliance on consistent application of that
254system; it is up to the author/donor to decide if he or she is willing
255to distribute software through any other system and a licensee cannot
256impose that choice.
257
258This section is intended to make thoroughly clear what is believed to
259be a consequence of the rest of this License.
260
261@item
262If the distribution and/or use of the Program is restricted in
263certain countries either by patents or by copyrighted interfaces, the
264original copyright holder who places the Program under this License
265may add an explicit geographical distribution limitation excluding
266those countries, so that distribution is permitted only in or among
267countries not thus excluded.  In such case, this License incorporates
268the limitation as if written in the body of this License.
269
270@item
271The Free Software Foundation may publish revised and/or new versions
272of the General Public License from time to time.  Such new versions will
273be similar in spirit to the present version, but may differ in detail to
274address new problems or concerns.
275
276Each version is given a distinguishing version number.  If the Program
277specifies a version number of this License which applies to it and ``any
278later version'', you have the option of following the terms and conditions
279either of that version or of any later version published by the Free
280Software Foundation.  If the Program does not specify a version number of
281this License, you may choose any version ever published by the Free Software
282Foundation.
283
284@item
285If you wish to incorporate parts of the Program into other free
286programs whose distribution conditions are different, write to the author
287to ask for permission.  For software which is copyrighted by the Free
288Software Foundation, write to the Free Software Foundation; we sometimes
289make exceptions for this.  Our decision will be guided by the two goals
290of preserving the free status of all derivatives of our free software and
291of promoting the sharing and reuse of software generally.
292
293@iftex
294@heading NO WARRANTY
295@end iftex
296@ifinfo
297@center NO WARRANTY
298
299@end ifinfo
300
301@item
302BECAUSE THE PROGRAM IS LICENSED FREE OF CHARGE, THERE IS NO WARRANTY
303FOR THE PROGRAM, TO THE EXTENT PERMITTED BY APPLICABLE LAW.  EXCEPT WHEN
304OTHERWISE STATED IN WRITING THE COPYRIGHT HOLDERS AND/OR OTHER PARTIES
305PROVIDE THE PROGRAM ``AS IS'' WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESSED
306OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
307MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.  THE ENTIRE RISK AS
308TO THE QUALITY AND PERFORMANCE OF THE PROGRAM IS WITH YOU.  SHOULD THE
309PROGRAM PROVE DEFECTIVE, YOU ASSUME THE COST OF ALL NECESSARY SERVICING,
310REPAIR OR CORRECTION.
311
312@item
313IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING
314WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MAY MODIFY AND/OR
315REDISTRIBUTE THE PROGRAM AS PERMITTED ABOVE, BE LIABLE TO YOU FOR DAMAGES,
316INCLUDING ANY GENERAL, SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING
317OUT OF THE USE OR INABILITY TO USE THE PROGRAM (INCLUDING BUT NOT LIMITED
318TO LOSS OF DATA OR DATA BEING RENDERED INACCURATE OR LOSSES SUSTAINED BY
319YOU OR THIRD PARTIES OR A FAILURE OF THE PROGRAM TO OPERATE WITH ANY OTHER
320PROGRAMS), EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE
321POSSIBILITY OF SUCH DAMAGES.
322@end enumerate
323
324@iftex
325@heading END OF TERMS AND CONDITIONS
326@end iftex
327@ifinfo
328@center END OF TERMS AND CONDITIONS
329
330@end ifinfo
331
332@page
333@unnumberedsubsec Appendix: How to Apply These Terms to Your New Programs
334
335  If you develop a new program, and you want it to be of the greatest
336possible use to the public, the best way to achieve this is to make it
337free software which everyone can redistribute and change under these terms.
338
339  To do so, attach the following notices to the program.  It is safest
340to attach them to the start of each source file to most effectively
341convey the exclusion of warranty; and each file should have at least
342the ``copyright'' line and a pointer to where the full notice is found.
343
344@smallexample
345@var{one line to give the program's name and a brief idea of what it does.}
346Copyright (C) @var{yyyy}  @var{name of author}
347
348This program is free software; you can redistribute it and/or modify
349it under the terms of the GNU General Public License as published by
350the Free Software Foundation; either version 2 of the License, or
351(at your option) any later version.
352
353This program is distributed in the hope that it will be useful,
354but WITHOUT ANY WARRANTY; without even the implied warranty of
355MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
356GNU General Public License for more details.
357
358You should have received a copy of the GNU General Public License
359along with this program; if not, write to the Free Software
360Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
361@end smallexample
362
363Also add information on how to contact you by electronic and paper mail.
364
365If the program is interactive, make it output a short notice like this
366when it starts in an interactive mode:
367
368@smallexample
369Gnomovision version 69, Copyright (C) 19@var{yy} @var{name of author}
370Gnomovision comes with ABSOLUTELY NO WARRANTY; for details type `show w'.
371This is free software, and you are welcome to redistribute it
372under certain conditions; type `show c' for details.
373@end smallexample
374
375The hypothetical commands @samp{show w} and @samp{show c} should show
376the appropriate parts of the General Public License.  Of course, the
377commands you use may be called something other than @samp{show w} and
378@samp{show c}; they could even be mouse-clicks or menu items---whatever
379suits your program.
380
381You should also get your employer (if you work as a programmer) or your
382school, if any, to sign a ``copyright disclaimer'' for the program, if
383necessary.  Here is a sample; alter the names:
384
385@example
386Yoyodyne, Inc., hereby disclaims all copyright interest in the program
387`Gnomovision' (which makes passes at compilers) written by James Hacker.
388
389@var{signature of Ty Coon}, 1 April 1989
390Ty Coon, President of Vice
391@end example
392
393This General Public License does not permit incorporating your program into
394proprietary programs.  If your program is a subroutine library, you may
395consider it more useful to permit linking proprietary applications with the
396library.  If this is what you want to do, use the GNU Library General
397Public License instead of this License.
398