1GNU General Public License
2==========================
3
4_Version 2, June 1991_
5
6_Copyright © 1989, 1991 Free Software Foundation, Inc.,_
7
8_51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA_
9
10Everyone is permitted to copy and distribute verbatim copies
11of this license document, but changing it is not allowed.
12
13### Preamble
14
15The licenses for most software are designed to take away your
16freedom to share and change it.  By contrast, the GNU General Public
17License is intended to guarantee your freedom to share and change free
18software--to make sure the software is free for all its users.  This
19General Public License applies to most of the Free Software
20Foundation's software and to any other program whose authors commit to
21using it.  (Some other Free Software Foundation software is covered by
22the GNU Lesser General Public License instead.)  You can apply it to
23your programs, too.
24
25When we speak of free software, we are referring to freedom, not
26price.  Our General Public Licenses are designed to make sure that you
27have the freedom to distribute copies of free software (and charge for
28this service if you wish), that you receive source code or can get it
29if you want it, that you can change the software or use pieces of it
30in new free programs; and that you know you can do these things.
31
32To protect your rights, we need to make restrictions that forbid
33anyone to deny you these rights or to ask you to surrender the rights.
34These restrictions translate to certain responsibilities for you if you
35distribute copies of the software, or if you modify it.
36
37For example, if you distribute copies of such a program, whether
38gratis or for a fee, you must give the recipients all the rights that
39you have.  You must make sure that they, too, receive or can get the
40source code.  And you must show them these terms so they know their
41rights.
42
43We protect your rights with two steps: **(1)** copyright the software, and
44**(2)** offer you this license which gives you legal permission to copy,
45distribute and/or modify the software.
46
47Also, for each author's protection and ours, we want to make certain
48that everyone understands that there is no warranty for this free
49software.  If the software is modified by someone else and passed on, we
50want its recipients to know that what they have is not the original, so
51that any problems introduced by others will not reflect on the original
52authors' reputations.
53
54Finally, any free program is threatened constantly by software
55patents.  We wish to avoid the danger that redistributors of a free
56program will individually obtain patent licenses, in effect making the
57program proprietary.  To prevent this, we have made it clear that any
58patent must be licensed for everyone's free use or not licensed at all.
59
60The precise terms and conditions for copying, distribution and
61modification follow.
62
63### TERMS AND CONDITIONS FOR COPYING, DISTRIBUTION AND MODIFICATION
64
65**0.** This License applies to any program or other work which contains
66a notice placed by the copyright holder saying it may be distributed
67under the terms of this General Public License.  The “Program”, below,
68refers to any such program or work, and a “work based on the Program”
69means either the Program or any derivative work under copyright law:
70that is to say, a work containing the Program or a portion of it,
71either verbatim or with modifications and/or translated into another
72language.  (Hereinafter, translation is included without limitation in
73the term “modification”.)  Each licensee is addressed as “you”.
74
75Activities other than copying, distribution and modification are not
76covered by this License; they are outside its scope.  The act of
77running the Program is not restricted, and the output from the Program
78is covered only if its contents constitute a work based on the
79Program (independent of having been made by running the Program).
80Whether that is true depends on what the Program does.
81
82**1.** You may copy and distribute verbatim copies of the Program's
83source code as you receive it, in any medium, provided that you
84conspicuously and appropriately publish on each copy an appropriate
85copyright notice and disclaimer of warranty; keep intact all the
86notices that refer to this License and to the absence of any warranty;
87and give any other recipients of the Program a copy of this License
88along with the Program.
89
90You may charge a fee for the physical act of transferring a copy, and
91you may at your option offer warranty protection in exchange for a fee.
92
93**2.** You may modify your copy or copies of the Program or any portion
94of it, thus forming a work based on the Program, and copy and
95distribute such modifications or work under the terms of Section 1
96above, provided that you also meet all of these conditions:
97
98* **a)** You must cause the modified files to carry prominent notices
99stating that you changed the files and the date of any change.
100* **b)** You must cause any work that you distribute or publish, that in
101whole or in part contains or is derived from the Program or any
102part thereof, to be licensed as a whole at no charge to all third
103parties under the terms of this License.
104* **c)** If the modified program normally reads commands interactively
105when run, you must cause it, when started running for such
106interactive use in the most ordinary way, to print or display an
107announcement including an appropriate copyright notice and a
108notice that there is no warranty (or else, saying that you provide
109a warranty) and that users may redistribute the program under
110these conditions, and telling the user how to view a copy of this
111License.  (Exception: if the Program itself is interactive but
112does not normally print such an announcement, your work based on
113the Program is not required to print an announcement.)
114
115These requirements apply to the modified work as a whole.  If
116identifiable sections of that work are not derived from the Program,
117and can be reasonably considered independent and separate works in
118themselves, then this License, and its terms, do not apply to those
119sections when you distribute them as separate works.  But when you
120distribute the same sections as part of a whole which is a work based
121on the Program, the distribution of the whole must be on the terms of
122this License, whose permissions for other licensees extend to the
123entire whole, and thus to each and every part regardless of who wrote it.
124
125Thus, it is not the intent of this section to claim rights or contest
126your rights to work written entirely by you; rather, the intent is to
127exercise the right to control the distribution of derivative or
128collective works based on the Program.
129
130In addition, mere aggregation of another work not based on the Program
131with the Program (or with a work based on the Program) on a volume of
132a storage or distribution medium does not bring the other work under
133the scope of this License.
134
135**3.** You may copy and distribute the Program (or a work based on it,
136under Section 2) in object code or executable form under the terms of
137Sections 1 and 2 above provided that you also do one of the following:
138
139* **a)** Accompany it with the complete corresponding machine-readable
140source code, which must be distributed under the terms of Sections
1411 and 2 above on a medium customarily used for software interchange; or,
142* **b)** Accompany it with a written offer, valid for at least three
143years, to give any third party, for a charge no more than your
144cost of physically performing source distribution, a complete
145machine-readable copy of the corresponding source code, to be
146distributed under the terms of Sections 1 and 2 above on a medium
147customarily used for software interchange; or,
148* **c)** Accompany it with the information you received as to the offer
149to distribute corresponding source code.  (This alternative is
150allowed only for noncommercial distribution and only if you
151received the program in object code or executable form with such
152an offer, in accord with Subsection b above.)
153
154The source code for a work means the preferred form of the work for
155making modifications to it.  For an executable work, complete source
156code means all the source code for all modules it contains, plus any
157associated interface definition files, plus the scripts used to
158control compilation and installation of the executable.  However, as a
159special exception, the source code distributed need not include
160anything that is normally distributed (in either source or binary
161form) with the major components (compiler, kernel, and so on) of the
162operating system on which the executable runs, unless that component
163itself accompanies the executable.
164
165If distribution of executable or object code is made by offering
166access to copy from a designated place, then offering equivalent
167access to copy the source code from the same place counts as
168distribution of the source code, even though third parties are not
169compelled to copy the source along with the object code.
170
171**4.** You may not copy, modify, sublicense, or distribute the Program
172except as expressly provided under this License.  Any attempt
173otherwise to copy, modify, sublicense or distribute the Program is
174void, and will automatically terminate your rights under this License.
175However, parties who have received copies, or rights, from you under
176this License will not have their licenses terminated so long as such
177parties remain in full compliance.
178
179**5.** You are not required to accept this License, since you have not
180signed it.  However, nothing else grants you permission to modify or
181distribute the Program or its derivative works.  These actions are
182prohibited by law if you do not accept this License.  Therefore, by
183modifying or distributing the Program (or any work based on the
184Program), you indicate your acceptance of this License to do so, and
185all its terms and conditions for copying, distributing or modifying
186the Program or works based on it.
187
188**6.** Each time you redistribute the Program (or any work based on the
189Program), the recipient automatically receives a license from the
190original licensor to copy, distribute or modify the Program subject to
191these terms and conditions.  You may not impose any further
192restrictions on the recipients' exercise of the rights granted herein.
193You are not responsible for enforcing compliance by third parties to
194this License.
195
196**7.** If, as a consequence of a court judgment or allegation of patent
197infringement or for any other reason (not limited to patent issues),
198conditions are imposed on you (whether by court order, agreement or
199otherwise) that contradict the conditions of this License, they do not
200excuse you from the conditions of this License.  If you cannot
201distribute so as to satisfy simultaneously your obligations under this
202License and any other pertinent obligations, then as a consequence you
203may not distribute the Program at all.  For example, if a patent
204license would not permit royalty-free redistribution of the Program by
205all those who receive copies directly or indirectly through you, then
206the only way you could satisfy both it and this License would be to
207refrain entirely from distribution of the Program.
208
209If any portion of this section is held invalid or unenforceable under
210any particular circumstance, the balance of the section is intended to
211apply and the section as a whole is intended to apply in other
212circumstances.
213
214It is not the purpose of this section to induce you to infringe any
215patents or other property right claims or to contest validity of any
216such claims; this section has the sole purpose of protecting the
217integrity of the free software distribution system, which is
218implemented by public license practices.  Many people have made
219generous contributions to the wide range of software distributed
220through that system in reliance on consistent application of that
221system; it is up to the author/donor to decide if he or she is willing
222to distribute software through any other system and a licensee cannot
223impose that choice.
224
225This section is intended to make thoroughly clear what is believed to
226be a consequence of the rest of this License.
227
228**8.** If the distribution and/or use of the Program is restricted in
229certain countries either by patents or by copyrighted interfaces, the
230original copyright holder who places the Program under this License
231may add an explicit geographical distribution limitation excluding
232those countries, so that distribution is permitted only in or among
233countries not thus excluded.  In such case, this License incorporates
234the limitation as if written in the body of this License.
235
236**9.** The Free Software Foundation may publish revised and/or new versions
237of the General Public License from time to time.  Such new versions will
238be similar in spirit to the present version, but may differ in detail to
239address new problems or concerns.
240
241Each version is given a distinguishing version number.  If the Program
242specifies a version number of this License which applies to it and “any
243later version”, you have the option of following the terms and conditions
244either of that version or of any later version published by the Free
245Software Foundation.  If the Program does not specify a version number of
246this License, you may choose any version ever published by the Free Software
247Foundation.
248
249**10.** If you wish to incorporate parts of the Program into other free
250programs whose distribution conditions are different, write to the author
251to ask for permission.  For software which is copyrighted by the Free
252Software Foundation, write to the Free Software Foundation; we sometimes
253make exceptions for this.  Our decision will be guided by the two goals
254of preserving the free status of all derivatives of our free software and
255of promoting the sharing and reuse of software generally.
256
257### NO WARRANTY
258
259**11.** BECAUSE THE PROGRAM IS LICENSED FREE OF CHARGE, THERE IS NO WARRANTY
260FOR THE PROGRAM, TO THE EXTENT PERMITTED BY APPLICABLE LAW.  EXCEPT WHEN
261OTHERWISE STATED IN WRITING THE COPYRIGHT HOLDERS AND/OR OTHER PARTIES
262PROVIDE THE PROGRAM “AS IS” WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESSED
263OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
264MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.  THE ENTIRE RISK AS
265TO THE QUALITY AND PERFORMANCE OF THE PROGRAM IS WITH YOU.  SHOULD THE
266PROGRAM PROVE DEFECTIVE, YOU ASSUME THE COST OF ALL NECESSARY SERVICING,
267REPAIR OR CORRECTION.
268
269**12.** IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING
270WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MAY MODIFY AND/OR
271REDISTRIBUTE THE PROGRAM AS PERMITTED ABOVE, BE LIABLE TO YOU FOR DAMAGES,
272INCLUDING ANY GENERAL, SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING
273OUT OF THE USE OR INABILITY TO USE THE PROGRAM (INCLUDING BUT NOT LIMITED
274TO LOSS OF DATA OR DATA BEING RENDERED INACCURATE OR LOSSES SUSTAINED BY
275YOU OR THIRD PARTIES OR A FAILURE OF THE PROGRAM TO OPERATE WITH ANY OTHER
276PROGRAMS), EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE
277POSSIBILITY OF SUCH DAMAGES.
278
279END OF TERMS AND CONDITIONS
280
281### How to Apply These Terms to Your New Programs
282
283If you develop a new program, and you want it to be of the greatest
284possible use to the public, the best way to achieve this is to make it
285free software which everyone can redistribute and change under these terms.
286
287To do so, attach the following notices to the program.  It is safest
288to attach them to the start of each source file to most effectively
289convey the exclusion of warranty; and each file should have at least
290the “copyright” line and a pointer to where the full notice is found.
291
292```
293<one line to give the program's name and a brief idea of what it does.>
294Copyright (C) <year>  <name of author>
295
296This program is free software; you can redistribute it and/or modify
297it under the terms of the GNU General Public License as published by
298the Free Software Foundation; either version 2 of the License, or
299(at your option) any later version.
300
301This program is distributed in the hope that it will be useful,
302but WITHOUT ANY WARRANTY; without even the implied warranty of
303MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
304GNU General Public License for more details.
305
306You should have received a copy of the GNU General Public License along
307with this program; if not, write to the Free Software Foundation, Inc.,
30851 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
309```
310
311Also add information on how to contact you by electronic and paper mail.
312
313If the program is interactive, make it output a short notice like this
314when it starts in an interactive mode:
315
316```
317Gnomovision version 69, Copyright (C) year name of author
318Gnomovision comes with ABSOLUTELY NO WARRANTY; for details type `show w'.
319This is free software, and you are welcome to redistribute it
320under certain conditions; type `show c' for details.
321```
322
323The hypothetical commands `show w` and `show c` should show the appropriate
324parts of the General Public License.  Of course, the commands you use may
325be called something other than `show w` and `show c`; they could even be
326mouse-clicks or menu items--whatever suits your program.
327
328You should also get your employer (if you work as a programmer) or your
329school, if any, to sign a “copyright disclaimer” for the program, if
330necessary.  Here is a sample; alter the names:
331
332```
333Yoyodyne, Inc., hereby disclaims all copyright interest in the program
334`Gnomovision' (which makes passes at compilers) written by James Hacker.
335
336<signature of Ty Coon>, 1 April 1989
337Ty Coon, President of Vice
338```
339
340This General Public License does not permit incorporating your program into
341proprietary programs.  If your program is a subroutine library, you may
342consider it more useful to permit linking proprietary applications with the
343library.  If this is what you want to do, use the GNU Lesser General
344Public License instead of this License.
345