1GNU GENERAL PUBLIC LICENSE
2
3Version 2, June 1991
4
5Copyright (C) 1989, 1991 Free Software Foundation, Inc.
6
751 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA
8
9Everyone is permitted to copy and distribute verbatim copies of this license
10document, but changing it is not allowed.
11
12Preamble
13
14The licenses for most software are designed to take away your freedom to share
15and change it. By contrast, the GNU General Public License is intended to
16guarantee your freedom to share and change free software--to make sure the
17software is free for all its users. This General Public License applies to
18most of the Free Software Foundation's software and to any other program whose
19authors commit to using it. (Some other Free Software Foundation software
20is covered by the GNU Lesser General Public License instead.) You can apply
21it to your programs, too.
22
23When we speak of free software, we are referring to freedom, not price. Our
24General Public Licenses are designed to make sure that you have the freedom
25to distribute copies of free software (and charge for this service if you
26wish), that you receive source code or can get it if you want it, that you
27can change the software or use pieces of it in new free programs; and that
28you know you can do these things.
29
30To protect your rights, we need to make restrictions that forbid anyone to
31deny you these rights or to ask you to surrender the rights. These restrictions
32translate to certain responsibilities for you if you distribute copies of
33the software, or if you modify it.
34
35For example, if you distribute copies of such a program, whether gratis or
36for a fee, you must give the recipients all the rights that you have. You
37must make sure that they, too, receive or can get the source code. And you
38must show them these terms so they know their rights.
39
40We protect your rights with two steps: (1) copyright the software, and (2)
41offer you this license which gives you legal permission to copy, distribute
42and/or modify the software.
43
44Also, for each author's protection and ours, we want to make certain that
45everyone understands that there is no warranty for this free software. If
46the software is modified by someone else and passed on, we want its recipients
47to know that what they have is not the original, so that any problems introduced
48by others will not reflect on the original authors' reputations.
49
50Finally, any free program is threatened constantly by software patents. We
51wish to avoid the danger that redistributors of a free program will individually
52obtain patent licenses, in effect making the program proprietary. To prevent
53this, we have made it clear that any patent must be licensed for everyone's
54free use or not licensed at all.
55
56The precise terms and conditions for copying, distribution and modification
57follow.
58
59TERMS AND CONDITIONS FOR COPYING, DISTRIBUTION AND MODIFICATION
60
610. This License applies to any program or other work which contains a notice
62placed by the copyright holder saying it may be distributed under the terms
63of this General Public License. The "Program", below, refers to any such program
64or work, and a "work based on the Program" means either the Program or any
65derivative work under copyright law: that is to say, a work containing the
66Program or a portion of it, either verbatim or with modifications and/or translated
67into another language. (Hereinafter, translation is included without limitation
68in the term "modification".) Each licensee is addressed as "you".
69
70Activities other than copying, distribution and modification are not covered
71by this License; they are outside its scope. The act of running the Program
72is not restricted, and the output from the Program is covered only if its
73contents constitute a work based on the Program (independent of having been
74made by running the Program). Whether that is true depends on what the Program
75does.
76
771. You may copy and distribute verbatim copies of the Program's source code
78as you receive it, in any medium, provided that you conspicuously and appropriately
79publish on each copy an appropriate copyright notice and disclaimer of warranty;
80keep intact all the notices that refer to this License and to the absence
81of any warranty; and give any other recipients of the Program a copy of this
82License along with the Program.
83
84You may charge a fee for the physical act of transferring a copy, and you
85may at your option offer warranty protection in exchange for a fee.
86
872. You may modify your copy or copies of the Program or any portion of it,
88thus forming a work based on the Program, and copy and distribute such modifications
89or work under the terms of Section 1 above, provided that you also meet all
90of these conditions:
91
92a) You must cause the modified files to carry prominent notices stating that
93you changed the files and the date of any change.
94
95b) You must cause any work that you distribute or publish, that in whole or
96in part contains or is derived from the Program or any part thereof, to be
97licensed as a whole at no charge to all third parties under the terms of this
98License.
99
100c) If the modified program normally reads commands interactively when run,
101you must cause it, when started running for such interactive use in the most
102ordinary way, to print or display an announcement including an appropriate
103copyright notice and a notice that there is no warranty (or else, saying that
104you provide a warranty) and that users may redistribute the program under
105these conditions, and telling the user how to view a copy of this License.
106(Exception: if the Program itself is interactive but does not normally print
107such an announcement, your work based on the Program is not required to print
108an announcement.)
109
110These requirements apply to the modified work as a whole. If identifiable
111sections of that work are not derived from the Program, and can be reasonably
112considered independent and separate works in themselves, then this License,
113and its terms, do not apply to those sections when you distribute them as
114separate works. But when you distribute the same sections as part of a whole
115which is a work based on the Program, the distribution of the whole must be
116on the terms of this License, whose permissions for other licensees extend
117to the entire whole, and thus to each and every part regardless of who wrote
118it.
119
120Thus, it is not the intent of this section to claim rights or contest your
121rights to work written entirely by you; rather, the intent is to exercise
122the right to control the distribution of derivative or collective works based
123on the Program.
124
125In addition, mere aggregation of another work not based on the Program with
126the Program (or with a work based on the Program) on a volume of a storage
127or distribution medium does not bring the other work under the scope of this
128License.
129
1303. You may copy and distribute the Program (or a work based on it, under Section
1312) in object code or executable form under the terms of Sections 1 and 2 above
132provided that you also do one of the following:
133
134a) Accompany it with the complete corresponding machine-readable source code,
135which must be distributed under the terms of Sections 1 and 2 above on a medium
136customarily used for software interchange; or,
137
138b) Accompany it with a written offer, valid for at least three years, to give
139any third party, for a charge no more than your cost of physically performing
140source distribution, a complete machine-readable copy of the corresponding
141source code, to be distributed under the terms of Sections 1 and 2 above on
142a medium customarily used for software interchange; or,
143
144c) Accompany it with the information you received as to the offer to distribute
145corresponding source code. (This alternative is allowed only for noncommercial
146distribution and only if you received the program in object code or executable
147form with such an offer, in accord with Subsection b above.)
148
149The source code for a work means the preferred form of the work for making
150modifications to it. For an executable work, complete source code means all
151the source code for all modules it contains, plus any associated interface
152definition files, plus the scripts used to control compilation and installation
153of the executable. However, as a special exception, the source code distributed
154need not include anything that is normally distributed (in either source or
155binary form) with the major components (compiler, kernel, and so on) of the
156operating system on which the executable runs, unless that component itself
157accompanies the executable.
158
159If distribution of executable or object code is made by offering access to
160copy from a designated place, then offering equivalent access to copy the
161source code from the same place counts as distribution of the source code,
162even though third parties are not compelled to copy the source along with
163the object code.
164
1654. You may not copy, modify, sublicense, or distribute the Program except
166as expressly provided under this License. Any attempt otherwise to copy, modify,
167sublicense or distribute the Program is void, and will automatically terminate
168your rights under this License. However, parties who have received copies,
169or rights, from you under this License will not have their licenses terminated
170so long as such parties remain in full compliance.
171
1725. You are not required to accept this License, since you have not signed
173it. However, nothing else grants you permission to modify or distribute the
174Program or its derivative works. These actions are prohibited by law if you
175do not accept this License. Therefore, by modifying or distributing the Program
176(or any work based on the Program), you indicate your acceptance of this License
177to do so, and all its terms and conditions for copying, distributing or modifying
178the Program or works based on it.
179
1806. Each time you redistribute the Program (or any work based on the Program),
181the recipient automatically receives a license from the original licensor
182to copy, distribute or modify the Program subject to these terms and conditions.
183You may not impose any further restrictions on the recipients' exercise of
184the rights granted herein. You are not responsible for enforcing compliance
185by third parties to this License.
186
1877. If, as a consequence of a court judgment or allegation of patent infringement
188or for any other reason (not limited to patent issues), conditions are imposed
189on you (whether by court order, agreement or otherwise) that contradict the
190conditions of this License, they do not excuse you from the conditions of
191this License. If you cannot distribute so as to satisfy simultaneously your
192obligations under this License and any other pertinent obligations, then as
193a consequence you may not distribute the Program at all. For example, if a
194patent license would not permit royalty-free redistribution of the Program
195by all those who receive copies directly or indirectly through you, then the
196only way you could satisfy both it and this License would be to refrain entirely
197from distribution of the Program.
198
199If any portion of this section is held invalid or unenforceable under any
200particular circumstance, the balance of the section is intended to apply and
201the section as a whole is intended to apply in other circumstances.
202
203It is not the purpose of this section to induce you to infringe any patents
204or other property right claims or to contest validity of any such claims;
205this section has the sole purpose of protecting the integrity of the free
206software distribution system, which is implemented by public license practices.
207Many people have made generous contributions to the wide range of software
208distributed through that system in reliance on consistent application of that
209system; it is up to the author/donor to decide if he or she is willing to
210distribute software through any other system and a licensee cannot impose
211that choice.
212
213This section is intended to make thoroughly clear what is believed to be a
214consequence of the rest of this License.
215
2168. If the distribution and/or use of the Program is restricted in certain
217countries either by patents or by copyrighted interfaces, the original copyright
218holder who places the Program under this License may add an explicit geographical
219distribution limitation excluding those countries, so that distribution is
220permitted only in or among countries not thus excluded. In such case, this
221License incorporates the limitation as if written in the body of this License.
222
2239. The Free Software Foundation may publish revised and/or new versions of
224the General Public License from time to time. Such new versions will be similar
225in spirit to the present version, but may differ in detail to address new
226problems or concerns.
227
228Each version is given a distinguishing version number. If the Program specifies
229a version number of this License which applies to it and "any later version",
230you have the option of following the terms and conditions either of that version
231or of any later version published by the Free Software Foundation. If the
232Program does not specify a version number of this License, you may choose
233any version ever published by the Free Software Foundation.
234
23510. If you wish to incorporate parts of the Program into other free programs
236whose distribution conditions are different, write to the author to ask for
237permission. For software which is copyrighted by the Free Software Foundation,
238write to the Free Software Foundation; we sometimes make exceptions for this.
239Our decision will be guided by the two goals of preserving the free status
240of all derivatives of our free software and of promoting the sharing and reuse
241of software generally.
242
243   NO WARRANTY
244
24511. BECAUSE THE PROGRAM IS LICENSED FREE OF CHARGE, THERE IS NO WARRANTY FOR
246THE PROGRAM, TO THE EXTENT PERMITTED BY APPLICABLE LAW. EXCEPT WHEN OTHERWISE
247STATED IN WRITING THE COPYRIGHT HOLDERS AND/OR OTHER PARTIES PROVIDE THE PROGRAM
248"AS IS" WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING,
249BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
250FOR A PARTICULAR PURPOSE. THE ENTIRE RISK AS TO THE QUALITY AND PERFORMANCE
251OF THE PROGRAM IS WITH YOU. SHOULD THE PROGRAM PROVE DEFECTIVE, YOU ASSUME
252THE COST OF ALL NECESSARY SERVICING, REPAIR OR CORRECTION.
253
25412. IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING
255WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MAY MODIFY AND/OR REDISTRIBUTE
256THE PROGRAM AS PERMITTED ABOVE, BE LIABLE TO YOU FOR DAMAGES, INCLUDING ANY
257GENERAL, SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING OUT OF THE USE
258OR INABILITY TO USE THE PROGRAM (INCLUDING BUT NOT LIMITED TO LOSS OF DATA
259OR DATA BEING RENDERED INACCURATE OR LOSSES SUSTAINED BY YOU OR THIRD PARTIES
260OR A FAILURE OF THE PROGRAM TO OPERATE WITH ANY OTHER PROGRAMS), EVEN IF SUCH
261HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES.
262END OF TERMS AND CONDITIONS
263
264How to Apply These Terms to Your New Programs
265
266If you develop a new program, and you want it to be of the greatest possible
267use to the public, the best way to achieve this is to make it free software
268which everyone can redistribute and change under these terms.
269
270To do so, attach the following notices to the program. It is safest to attach
271them to the start of each source file to most effectively convey the exclusion
272of warranty; and each file should have at least the "copyright" line and a
273pointer to where the full notice is found.
274
275<one line to give the program's name and an idea of what it does.>
276
277Copyright (C) <yyyy> <name of author>
278
279This program is free software; you can redistribute it and/or modify it under
280the terms of the GNU General Public License as published by the Free Software
281Foundation; either version 2 of the License, or (at your option) any later
282version.
283
284This program is distributed in the hope that it will be useful, but WITHOUT
285ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
286FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
287
288You should have received a copy of the GNU General Public License along with
289this program; if not, write to the Free Software Foundation, Inc., 51 Franklin
290Street, Fifth Floor, Boston, MA 02110-1301, USA.
291
292Also add information on how to contact you by electronic and paper mail.
293
294If the program is interactive, make it output a short notice like this when
295it starts in an interactive mode:
296
297Gnomovision version 69, Copyright (C) year name of author Gnomovision comes
298with ABSOLUTELY NO WARRANTY; for details type `show w'. This is free software,
299and you are welcome to redistribute it under certain conditions; type `show
300c' for details.
301
302The hypothetical commands `show w' and `show c' should show the appropriate
303parts of the General Public License. Of course, the commands you use may be
304called something other than `show w' and `show c'; they could even be mouse-clicks
305or menu items--whatever suits your program.
306
307You should also get your employer (if you work as a programmer) or your school,
308if any, to sign a "copyright disclaimer" for the program, if necessary. Here
309is a sample; alter the names:
310
311Yoyodyne, Inc., hereby disclaims all copyright interest in the program `Gnomovision'
312(which makes passes at compilers) written by James Hacker.
313
314<signature of Ty Coon>, 1 April 1989 Ty Coon, President of Vice This General
315Public License does not permit incorporating your program into proprietary
316programs. If your program is a subroutine library, you may consider it more
317useful to permit linking proprietary applications with the library. If this
318is what you want to do, use the GNU Lesser General Public License instead
319of this License.
320