1GNU GENERAL PUBLIC LICENSE
2
3Version 2, June 1991
4
5Copyright (C) 1989, 1991 Free Software Foundation, Inc.
659 Temple Place - Suite 330, Boston, MA  02111-1307, USA
7
8Everyone is permitted to copy and distribute verbatim copies
9of this license document, but changing it is not allowed.
10
11Preamble
12
13The licenses for most software are designed to take away your freedom to
14share and change it. By contrast, the GNU General Public License is intended
15to guarantee your freedom to share and change free software--to make sure
16the software is free for all its users. This General Public License applies
17to most of the Free Software Foundation's software and to any other program
18whose authors commit to using it. (Some other Free Software Foundation
19software is covered by the GNU Library General Public License instead.) You
20can apply it to your programs, too.
21
22When we speak of free software, we are referring to freedom, not price. Our
23General Public Licenses are designed to make sure that you have the freedom
24to distribute copies of free software (and charge for this service if you
25wish), that you receive source code or can get it if you want it, that you
26can change the software or use pieces of it in new free programs; and that
27you know you can do these things.
28
29To protect your rights, we need to make restrictions that forbid anyone to
30deny you these rights or to ask you to surrender the rights. These
31restrictions translate to certain responsibilities for you if you distribute
32copies of the software, or if you modify it.
33
34For example, if you distribute copies of such a program, whether gratis or
35for a fee, you must give the recipients all the rights that you have. You
36must make sure that they, too, receive or can get the source code. And you
37must show them these terms so they know their rights.
38
39We protect your rights with two steps: (1) copyright the software, and (2)
40offer you this license which gives you legal permission to copy, distribute
41and/or modify the software.
42
43Also, for each author's protection and ours, we want to make certain that
44everyone understands that there is no warranty for this free software. If
45the software is modified by someone else and passed on, we want its
46recipients to know that what they have is not the original, so that any
47problems introduced by others will not reflect on the original authors'
48reputations.
49
50Finally, any free program is threatened constantly by software patents. We
51wish to avoid the danger that redistributors of a free program will
52individually obtain patent licenses, in effect making the program
53proprietary. To prevent this, we have made it clear that any patent must be
54licensed for everyone's free 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
64program or work, and a "work based on the Program" means either the Program
65or any derivative work under copyright law: that is to say, a work
66containing the Program or a portion of it, either verbatim or with
67modifications and/or translated into another language. (Hereinafter,
68translation is included without limitation in the term "modification".) Each
69licensee is addressed as "you".
70
71Activities other than copying, distribution and modification are not covered
72by this License; they are outside its scope. The act of running the Program
73is not restricted, and the output from the Program is covered only if its
74contents constitute a work based on the Program (independent of having been
75made by running the Program). Whether that is true depends on what the
76Program does.
77
781. You may copy and distribute verbatim copies of the Program's source code
79as you receive it, in any medium, provided that you conspicuously and
80appropriately publish on each copy an appropriate copyright notice and
81disclaimer of warranty; keep intact all the notices that refer to this
82License and to the absence of any warranty; and give any other recipients of
83the Program a copy of this License along with the Program.
84
85You may charge a fee for the physical act of transferring a copy, and you
86may at your option offer warranty protection in exchange for a fee.
87
882. You may modify your copy or copies of the Program or any portion of it,
89thus forming a work based on the Program, and copy and distribute such
90modifications or work under the terms of Section 1 above, provided that you
91also meet all of these conditions:
92
93   * a) You must cause the modified files to carry prominent notices stating
94     that you changed the files and the date of any change.
95
96   * b) You must cause any work that you distribute or publish, that in
97     whole or in part contains or is derived from the Program or any part
98     thereof, to be licensed as a whole at no charge to all third parties
99     under the terms of this License.
100
101   * c) If the modified program normally reads commands interactively when
102     run, you must cause it, when started running for such interactive use
103     in the most ordinary way, to print or display an announcement including
104     an appropriate copyright notice and a notice that there is no warranty
105     (or else, saying that you provide a warranty) and that users may
106     redistribute the program under these conditions, and telling the user
107     how to view a copy of this License. (Exception: if the Program itself
108     is interactive but does not normally print such an announcement, your
109     work based on the Program is not required to print an announcement.)
110
111These requirements apply to the modified work as a whole. If identifiable
112sections of that work are not derived from the Program, and can be
113reasonably considered independent and separate works in themselves, then
114this License, and its terms, do not apply to those sections when you
115distribute them as separate works. But when you distribute the same sections
116as part of a whole which is a work based on the Program, the distribution of
117the whole must be on the terms of this License, whose permissions for other
118licensees extend to the entire whole, and thus to each and every part
119regardless of who wrote it.
120
121Thus, it is not the intent of this section to claim rights or contest your
122rights to work written entirely by you; rather, the intent is to exercise
123the right to control the distribution of derivative or collective works
124based on the Program.
125
126In addition, mere aggregation of another work not based on the Program with
127the Program (or with a work based on the Program) on a volume of a storage
128or distribution medium does not bring the other work under the scope of this
129License.
130
1313. You may copy and distribute the Program (or a work based on it, under
132Section 2) in object code or executable form under the terms of Sections 1
133and 2 above provided that you also do one of the following:
134
135   * a) Accompany it with the complete corresponding machine-readable source
136     code, which must be distributed under the terms of Sections 1 and 2
137     above on a medium customarily used for software interchange; or,
138
139   * b) Accompany it with a written offer, valid for at least three years,
140     to give any third party, for a charge no more than your cost of
141     physically performing source distribution, a complete machine-readable
142     copy of the corresponding source code, to be distributed under the
143     terms of Sections 1 and 2 above on a medium customarily used for
144     software interchange; or,
145
146   * c) Accompany it with the information you received as to the offer to
147     distribute corresponding source code. (This alternative is allowed only
148     for noncommercial distribution and only if you received the program in
149     object code or executable form with such an offer, in accord with
150     Subsection b above.)
151
152The source code for a work means the preferred form of the work for making
153modifications to it. For an executable work, complete source code means all
154the source code for all modules it contains, plus any associated interface
155definition files, plus the scripts used to control compilation and
156installation of the executable. However, as a special exception, the source
157code distributed need not include anything that is normally distributed (in
158either source or binary form) with the major components (compiler, kernel,
159and so on) of the operating system on which the executable runs, unless that
160component itself accompanies the executable.
161
162If distribution of executable or object code is made by offering access to
163copy from a designated place, then offering equivalent access to copy the
164source code from the same place counts as distribution of the source code,
165even though third parties are not compelled to copy the source along with
166the object code.
167
1684. You may not copy, modify, sublicense, or distribute the Program except as
169expressly provided under this License. Any attempt otherwise to copy,
170modify, sublicense or distribute the Program is void, and will automatically
171terminate your rights under this License. However, parties who have received
172copies, or rights, from you under this License will not have their licenses
173terminated so long as such parties remain in full compliance.
174
1755. You are not required to accept this License, since you have not signed
176it. However, nothing else grants you permission to modify or distribute the
177Program or its derivative works. These actions are prohibited by law if you
178do not accept this License. Therefore, by modifying or distributing the
179Program (or any work based on the Program), you indicate your acceptance of
180this License to do so, and all its terms and conditions for copying,
181distributing or modifying the Program or works based on it.
182
1836. Each time you redistribute the Program (or any work based on the
184Program), the recipient automatically receives a license from the original
185licensor to copy, distribute or modify the Program subject to these terms
186and conditions. You may not impose any further restrictions on the
187recipients' exercise of the rights granted herein. You are not responsible
188for enforcing compliance by third parties to this License.
189
1907. If, as a consequence of a court judgment or allegation of patent
191infringement or for any other reason (not limited to patent issues),
192conditions are imposed on you (whether by court order, agreement or
193otherwise) that contradict the conditions of this License, they do not
194excuse you from the conditions of this License. If you cannot distribute so
195as to satisfy simultaneously your obligations under this License and any
196other pertinent obligations, then as a consequence you may not distribute
197the Program at all. For example, if a patent license would not permit
198royalty-free redistribution of the Program by all those who receive copies
199directly or indirectly through you, then the only way you could satisfy both
200it and this License would be to refrain entirely from distribution of the
201Program.
202
203If any portion of this section is held invalid or unenforceable under any
204particular circumstance, the balance of the section is intended to apply and
205the section as a whole is intended to apply in other circumstances.
206
207It is not the purpose of this section to induce you to infringe any patents
208or other property right claims or to contest validity of any such claims;
209this section has the sole purpose of protecting the integrity of the free
210software distribution system, which is implemented by public license
211practices. Many people have made generous contributions to the wide range of
212software distributed through that system in reliance on consistent
213application of that system; it is up to the author/donor to decide if he or
214she is willing to distribute software through any other system and a
215licensee cannot impose that choice.
216
217This section is intended to make thoroughly clear what is believed to be a
218consequence of the rest of this License.
219
2208. If the distribution and/or use of the Program is restricted in certain
221countries either by patents or by copyrighted interfaces, the original
222copyright holder who places the Program under this License may add an
223explicit geographical distribution limitation excluding those countries, so
224that distribution is permitted only in or among countries not thus excluded.
225In such case, this License incorporates the limitation as if written in the
226body of this License.
227
2289. The Free Software Foundation may publish revised and/or new versions of
229the General Public License from time to time. Such new versions will be
230similar in spirit to the present version, but may differ in detail to
231address new problems or concerns.
232
233Each version is given a distinguishing version number. If the Program
234specifies a version number of this License which applies to it and "any
235later version", you have the option of following the terms and conditions
236either of that version or of any later version published by the Free
237Software Foundation. If the Program does not specify a version number of
238this License, you may choose any version ever published by the Free Software
239Foundation.
240
24110. If you wish to incorporate parts of the Program into other free programs
242whose distribution conditions are different, write to the author to ask for
243permission. For software which is copyrighted by the Free Software
244Foundation, write to the Free Software Foundation; we sometimes make
245exceptions for this. Our decision will be guided by the two goals of
246preserving the free status of all derivatives of our free software and of
247promoting the sharing and reuse of software generally.
248
249NO WARRANTY
250
25111. BECAUSE THE PROGRAM IS LICENSED FREE OF CHARGE, THERE IS NO WARRANTY FOR
252THE PROGRAM, TO THE EXTENT PERMITTED BY APPLICABLE LAW. EXCEPT WHEN
253OTHERWISE STATED IN WRITING THE COPYRIGHT HOLDERS AND/OR OTHER PARTIES
254PROVIDE THE PROGRAM "AS IS" WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESSED
255OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
256MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. THE ENTIRE RISK AS TO
257THE QUALITY AND PERFORMANCE OF THE PROGRAM IS WITH YOU. SHOULD THE PROGRAM
258PROVE DEFECTIVE, YOU ASSUME THE COST OF ALL NECESSARY SERVICING, REPAIR OR
259CORRECTION.
260
26112. IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING
262WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MAY MODIFY AND/OR
263REDISTRIBUTE THE PROGRAM AS PERMITTED ABOVE, BE LIABLE TO YOU FOR DAMAGES,
264INCLUDING ANY GENERAL, SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING
265OUT OF THE USE OR INABILITY TO USE THE PROGRAM (INCLUDING BUT NOT LIMITED TO
266LOSS OF DATA OR DATA BEING RENDERED INACCURATE OR LOSSES SUSTAINED BY YOU OR
267THIRD PARTIES OR A FAILURE OF THE PROGRAM TO OPERATE WITH ANY OTHER
268PROGRAMS), EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE
269POSSIBILITY OF SUCH DAMAGES.
270
271END OF TERMS AND CONDITIONS
272