2 @unnumbered GNU General Public License
4 @cindex GPL, GNU General Public License
5 @center Version 2, June 1991
8 Copyright @copyright{} 1989, 1991 Free Software Foundation, Inc.
9 59 Temple Place -- Suite 330, Boston, MA 02111-1307, USA
11 Everyone is permitted to copy and distribute verbatim copies
12 of this license document, but changing it is not allowed.
17 The licenses for most software are designed to take away your
18 freedom to share and change it. By contrast, the GNU General Public
19 License is intended to guarantee your freedom to share and change free
20 software---to make sure the software is free for all its users. This
21 General Public License applies to most of the Free Software
22 Foundation's software and to any other program whose authors commit to
23 using it. (Some other Free Software Foundation software is covered by
24 the GNU Library General Public License instead.) You can apply it to
27 When we speak of free software, we are referring to freedom, not
28 price. Our General Public Licenses are designed to make sure that you
29 have the freedom to distribute copies of free software (and charge for
30 this service if you wish), that you receive source code or can get it
31 if you want it, that you can change the software or use pieces of it
32 in new free programs; and that you know you can do these things.
34 To protect your rights, we need to make restrictions that forbid
35 anyone to deny you these rights or to ask you to surrender the rights.
36 These restrictions translate to certain responsibilities for you if you
37 distribute copies of the software, or if you modify it.
39 For example, if you distribute copies of such a program, whether
40 gratis or for a fee, you must give the recipients all the rights that
41 you have. You must make sure that they, too, receive or can get the
42 source code. And you must show them these terms so they know their
45 We protect your rights with two steps: (1) copyright the software, and
46 (2) offer you this license which gives you legal permission to copy,
47 distribute and/or modify the software.
49 Also, for each author's protection and ours, we want to make certain
50 that everyone understands that there is no warranty for this free
51 software. If the software is modified by someone else and passed on, we
52 want its recipients to know that what they have is not the original, so
53 that any problems introduced by others will not reflect on the original
56 Finally, any free program is threatened constantly by software
57 patents. We wish to avoid the danger that redistributors of a free
58 program will individually obtain patent licenses, in effect making the
59 program proprietary. To prevent this, we have made it clear that any
60 patent must be licensed for everyone's free use or not licensed at all.
62 The precise terms and conditions for copying, distribution and
66 @heading TERMS AND CONDITIONS FOR COPYING, DISTRIBUTION AND MODIFICATION
69 @center TERMS AND CONDITIONS FOR COPYING, DISTRIBUTION AND MODIFICATION
74 This License applies to any program or other work which contains
75 a notice placed by the copyright holder saying it may be distributed
76 under the terms of this General Public License. The ``Program'', below,
77 refers to any such program or work, and a ``work based on the Program''
78 means either the Program or any derivative work under copyright law:
79 that is to say, a work containing the Program or a portion of it,
80 either verbatim or with modifications and/or translated into another
81 language. (Hereinafter, translation is included without limitation in
82 the term ``modification''.) Each licensee is addressed as ``you''.
84 Activities other than copying, distribution and modification are not
85 covered by this License; they are outside its scope. The act of
86 running the Program is not restricted, and the output from the Program
87 is covered only if its contents constitute a work based on the
88 Program (independent of having been made by running the Program).
89 Whether that is true depends on what the Program does.
92 You may copy and distribute verbatim copies of the Program's
93 source code as you receive it, in any medium, provided that you
94 conspicuously and appropriately publish on each copy an appropriate
95 copyright notice and disclaimer of warranty; keep intact all the
96 notices that refer to this License and to the absence of any warranty;
97 and give any other recipients of the Program a copy of this License
98 along with the Program.
100 You may charge a fee for the physical act of transferring a copy, and
101 you may at your option offer warranty protection in exchange for a fee.
104 You may modify your copy or copies of the Program or any portion
105 of it, thus forming a work based on the Program, and copy and
106 distribute such modifications or work under the terms of Section 1
107 above, provided that you also meet all of these conditions:
111 You must cause the modified files to carry prominent notices
112 stating that you changed the files and the date of any change.
115 You must cause any work that you distribute or publish, that in
116 whole or in part contains or is derived from the Program or any
117 part thereof, to be licensed as a whole at no charge to all third
118 parties under the terms of this License.
121 If the modified program normally reads commands interactively
122 when run, you must cause it, when started running for such
123 interactive use in the most ordinary way, to print or display an
124 announcement including an appropriate copyright notice and a
125 notice that there is no warranty (or else, saying that you provide
126 a warranty) and that users may redistribute the program under
127 these conditions, and telling the user how to view a copy of this
128 License. (Exception: if the Program itself is interactive but
129 does not normally print such an announcement, your work based on
130 the Program is not required to print an announcement.)
133 These requirements apply to the modified work as a whole. If
134 identifiable sections of that work are not derived from the Program,
135 and can be reasonably considered independent and separate works in
136 themselves, then this License, and its terms, do not apply to those
137 sections when you distribute them as separate works. But when you
138 distribute the same sections as part of a whole which is a work based
139 on the Program, the distribution of the whole must be on the terms of
140 this License, whose permissions for other licensees extend to the
141 entire whole, and thus to each and every part regardless of who wrote it.
143 Thus, it is not the intent of this section to claim rights or contest
144 your rights to work written entirely by you; rather, the intent is to
145 exercise the right to control the distribution of derivative or
146 collective works based on the Program.
148 In addition, mere aggregation of another work not based on the Program
149 with the Program (or with a work based on the Program) on a volume of
150 a storage or distribution medium does not bring the other work under
151 the scope of this License.
154 You may copy and distribute the Program (or a work based on it,
155 under Section 2) in object code or executable form under the terms of
156 Sections 1 and 2 above provided that you also do one of the following:
160 Accompany it with the complete corresponding machine-readable
161 source code, which must be distributed under the terms of Sections
162 1 and 2 above on a medium customarily used for software interchange; or,
165 Accompany it with a written offer, valid for at least three
166 years, to give any third party, for a charge no more than your
167 cost of physically performing source distribution, a complete
168 machine-readable copy of the corresponding source code, to be
169 distributed under the terms of Sections 1 and 2 above on a medium
170 customarily used for software interchange; or,
173 Accompany it with the information you received as to the offer
174 to distribute corresponding source code. (This alternative is
175 allowed only for noncommercial distribution and only if you
176 received the program in object code or executable form with such
177 an offer, in accord with Subsection b above.)
180 The source code for a work means the preferred form of the work for
181 making modifications to it. For an executable work, complete source
182 code means all the source code for all modules it contains, plus any
183 associated interface definition files, plus the scripts used to
184 control compilation and installation of the executable. However, as a
185 special exception, the source code distributed need not include
186 anything that is normally distributed (in either source or binary
187 form) with the major components (compiler, kernel, and so on) of the
188 operating system on which the executable runs, unless that component
189 itself accompanies the executable.
191 If distribution of executable or object code is made by offering
192 access to copy from a designated place, then offering equivalent
193 access to copy the source code from the same place counts as
194 distribution of the source code, even though third parties are not
195 compelled to copy the source along with the object code.
198 You may not copy, modify, sublicense, or distribute the Program
199 except as expressly provided under this License. Any attempt
200 otherwise to copy, modify, sublicense or distribute the Program is
201 void, and will automatically terminate your rights under this License.
202 However, parties who have received copies, or rights, from you under
203 this License will not have their licenses terminated so long as such
204 parties remain in full compliance.
207 You are not required to accept this License, since you have not
208 signed it. However, nothing else grants you permission to modify or
209 distribute the Program or its derivative works. These actions are
210 prohibited by law if you do not accept this License. Therefore, by
211 modifying or distributing the Program (or any work based on the
212 Program), you indicate your acceptance of this License to do so, and
213 all its terms and conditions for copying, distributing or modifying
214 the Program or works based on it.
217 Each time you redistribute the Program (or any work based on the
218 Program), the recipient automatically receives a license from the
219 original licensor to copy, distribute or modify the Program subject to
220 these terms and conditions. You may not impose any further
221 restrictions on the recipients' exercise of the rights granted herein.
222 You are not responsible for enforcing compliance by third parties to
226 If, as a consequence of a court judgment or allegation of patent
227 infringement or for any other reason (not limited to patent issues),
228 conditions are imposed on you (whether by court order, agreement or
229 otherwise) that contradict the conditions of this License, they do not
230 excuse you from the conditions of this License. If you cannot
231 distribute so as to satisfy simultaneously your obligations under this
232 License and any other pertinent obligations, then as a consequence you
233 may not distribute the Program at all. For example, if a patent
234 license would not permit royalty-free redistribution of the Program by
235 all those who receive copies directly or indirectly through you, then
236 the only way you could satisfy both it and this License would be to
237 refrain entirely from distribution of the Program.
239 If any portion of this section is held invalid or unenforceable under
240 any particular circumstance, the balance of the section is intended to
241 apply and the section as a whole is intended to apply in other
244 It is not the purpose of this section to induce you to infringe any
245 patents or other property right claims or to contest validity of any
246 such claims; this section has the sole purpose of protecting the
247 integrity of the free software distribution system, which is
248 implemented by public license practices. Many people have made
249 generous contributions to the wide range of software distributed
250 through that system in reliance on consistent application of that
251 system; it is up to the author/donor to decide if he or she is willing
252 to distribute software through any other system and a licensee cannot
255 This section is intended to make thoroughly clear what is believed to
256 be a consequence of the rest of this License.
259 If the distribution and/or use of the Program is restricted in
260 certain countries either by patents or by copyrighted interfaces, the
261 original copyright holder who places the Program under this License
262 may add an explicit geographical distribution limitation excluding
263 those countries, so that distribution is permitted only in or among
264 countries not thus excluded. In such case, this License incorporates
265 the limitation as if written in the body of this License.
268 The Free Software Foundation may publish revised and/or new versions
269 of the General Public License from time to time. Such new versions will
270 be similar in spirit to the present version, but may differ in detail to
271 address new problems or concerns.
273 Each version is given a distinguishing version number. If the Program
274 specifies a version number of this License which applies to it and ``any
275 later version'', you have the option of following the terms and conditions
276 either of that version or of any later version published by the Free
277 Software Foundation. If the Program does not specify a version number of
278 this License, you may choose any version ever published by the Free Software
282 If you wish to incorporate parts of the Program into other free
283 programs whose distribution conditions are different, write to the author
284 to ask for permission. For software which is copyrighted by the Free
285 Software Foundation, write to the Free Software Foundation; we sometimes
286 make exceptions for this. Our decision will be guided by the two goals
287 of preserving the free status of all derivatives of our free software and
288 of promoting the sharing and reuse of software generally.
298 BECAUSE THE PROGRAM IS LICENSED FREE OF CHARGE, THERE IS NO WARRANTY
299 FOR THE PROGRAM, TO THE EXTENT PERMITTED BY APPLICABLE LAW. EXCEPT WHEN
300 OTHERWISE STATED IN WRITING THE COPYRIGHT HOLDERS AND/OR OTHER PARTIES
301 PROVIDE THE PROGRAM ``AS IS'' WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESSED
302 OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
303 MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. THE ENTIRE RISK AS
304 TO THE QUALITY AND PERFORMANCE OF THE PROGRAM IS WITH YOU. SHOULD THE
305 PROGRAM PROVE DEFECTIVE, YOU ASSUME THE COST OF ALL NECESSARY SERVICING,
306 REPAIR OR CORRECTION.
309 IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING
310 WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MAY MODIFY AND/OR
311 REDISTRIBUTE THE PROGRAM AS PERMITTED ABOVE, BE LIABLE TO YOU FOR DAMAGES,
312 INCLUDING ANY GENERAL, SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING
313 OUT OF THE USE OR INABILITY TO USE THE PROGRAM (INCLUDING BUT NOT LIMITED
314 TO LOSS OF DATA OR DATA BEING RENDERED INACCURATE OR LOSSES SUSTAINED BY
315 YOU OR THIRD PARTIES OR A FAILURE OF THE PROGRAM TO OPERATE WITH ANY OTHER
316 PROGRAMS), EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE
317 POSSIBILITY OF SUCH DAMAGES.
321 @heading END OF TERMS AND CONDITIONS
324 @center END OF TERMS AND CONDITIONS
328 @heading How to Apply These Terms to Your New Programs
330 If you develop a new program, and you want it to be of the greatest
331 possible use to the public, the best way to achieve this is to make it
332 free software which everyone can redistribute and change under these terms.
334 To do so, attach the following notices to the program. It is safest
335 to attach them to the start of each source file to most effectively
336 convey the exclusion of warranty; and each file should have at least
337 the ``copyright'' line and a pointer to where the full notice is found.
340 @var{one line to give the program's name and an idea of what it does.}
341 Copyright (C) 19@var{yy} @var{name of author}
343 This program is free software; you can redistribute it and/or
344 modify it under the terms of the GNU General Public License
345 as published by the Free Software Foundation; either version 2
346 of the License, or (at your option) any later version.
348 This program is distributed in the hope that it will be useful,
349 but WITHOUT ANY WARRANTY; without even the implied warranty of
350 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
351 GNU General Public License for more details.
353 You should have received a copy of the GNU General Public License along
354 with this program; if not, write to the Free Software Foundation, Inc.,
355 59 Temple Place, Suite 330, Boston, MA 02111-1307, USA.
358 Also add information on how to contact you by electronic and paper mail.
360 If the program is interactive, make it output a short notice like this
361 when it starts in an interactive mode:
364 Gnomovision version 69, Copyright (C) 19@var{yy} @var{name of author}
365 Gnomovision comes with ABSOLUTELY NO WARRANTY; for details
366 type `show w'. This is free software, and you are welcome
367 to redistribute it under certain conditions; type `show c'
371 The hypothetical commands @samp{show w} and @samp{show c} should show
372 the appropriate parts of the General Public License. Of course, the
373 commands you use may be called something other than @samp{show w} and
374 @samp{show c}; they could even be mouse-clicks or menu items---whatever
377 You should also get your employer (if you work as a programmer) or your
378 school, if any, to sign a ``copyright disclaimer'' for the program, if
379 necessary. Here is a sample; alter the names:
383 Yoyodyne, Inc., hereby disclaims all copyright
384 interest in the program `Gnomovision'
385 (which makes passes at compilers) written
388 @var{signature of Ty Coon}, 1 April 1989
389 Ty Coon, President of Vice
393 This General Public License does not permit incorporating your program into
394 proprietary programs. If your program is a subroutine library, you may
395 consider it more useful to permit linking proprietary applications with the
396 library. If this is what you want to do, use the GNU Library General
397 Public License instead of this License.