]> git.saurik.com Git - wxWidgets.git/blob - docs/lgpl.txt
Made DC cacheing less obstrusive
[wxWidgets.git] / docs / lgpl.txt
1
2 GNU LIBRARY GENERAL PUBLIC LICENSE
3 ==================================
4 Version 2, June 1991
5
6 Copyright (C) 1991 Free Software Foundation, Inc.
7 675 Mass Ave, Cambridge, MA 02139, USA
8 Everyone is permitted to copy and distribute verbatim copies
9 of this license document, but changing it is not allowed.
10
11 [This is the first released version of the library GPL. It is
12 numbered 2 because it goes with version 2 of the ordinary GPL.]
13
14 Preamble
15
16 The licenses for most software are designed to take away your
17 freedom to share and change it. By contrast, the GNU General
18 Public Licenses are intended to guarantee your freedom to share
19 and change free software--to make sure the software is free for
20 all its users.
21
22 This license, the Library General Public License, applies to
23 some specially designated Free Software Foundation software, and
24 to any other libraries whose authors decide to use it. You can
25 use it for your libraries, too.
26
27 When we speak of free software, we are referring to freedom, not
28 price. Our General Public Licenses are designed to make sure
29 that you have the freedom to distribute copies of free software
30 (and charge for this service if you wish), that you receive
31 source code or can get it if you want it, that you can change
32 the software or use pieces of it in new free programs; and that
33 you know you can do these things.
34
35 To protect your rights, we need to make restrictions that forbid
36 anyone to deny you these rights or to ask you to surrender the
37 rights. These restrictions translate to certain responsibilities
38 for you if you distribute copies of the library, or if you
39 modify it.
40
41 For example, if you distribute copies of the library, whether
42 gratis or for a fee, you must give the recipients all the rights
43 that we gave you. You must make sure that they, too, receive or
44 can get the source code. If you link a program with the
45 library, you must provide complete object files to the
46 recipients so that they can relink them with the library, after
47 making changes to the library and recompiling it. And you must
48 show them these terms so they know their rights.
49
50 Our method of protecting your rights has two steps: (1)
51 copyright the library, and (2) offer you this license which
52 gives you legal permission to copy, distribute and/or modify the
53 library.
54
55 Also, for each distributor's protection, we want to make certain
56 that everyone understands that there is no warranty for this
57 free library. If the library is modified by someone else and
58 passed on, we want its recipients to know that what they have is
59 not the original version, so that any problems introduced by
60 others will not reflect on the original authors' reputations.
61
62 Finally, any free program is threatened constantly by software
63 patents. We wish to avoid the danger that companies
64 distributing free software will individually obtain patent
65 licenses, thus in effect transforming the program into
66 proprietary software. To prevent this, we have made it clear
67 that any patent must be licensed for everyone's free use or not
68 licensed at all.
69
70 Most GNU software, including some libraries, is covered by the
71 ordinary GNU General Public License, which was designed for
72 utility programs. This license, the GNU Library General Public
73 License, applies to certain designated libraries. This license
74 is quite different from the ordinary one; be sure to read it in
75 full, and don't assume that anything in it is the same as in the
76 ordinary license.
77
78 The reason we have a separate public license for some libraries
79 is that they blur the distinction we usually make between
80 modifying or adding to a program and simply using it. Linking a
81 program with a library, without changing the library, is in some
82 sense simply using the library, and is analogous to running a
83 utility program or application program. However, in a textual
84 and legal sense, the linked executable is a combined work, a
85 derivative of the original library, and the ordinary General
86 Public License treats it as such.
87
88 Because of this blurred distinction, using the ordinary General
89 Public License for libraries did not effectively promote
90 software sharing, because most developers did not use the
91 libraries. We concluded that weaker conditions might promote
92 sharing better.
93
94 However, unrestricted linking of non-free programs would deprive
95 the users of those programs of all benefit from the free status
96 of the libraries themselves. This Library General Public
97 License is intended to permit developers of non-free programs to
98 use free libraries, while preserving your freedom as a user of
99 such programs to change the free libraries that are incorporated
100 in them. (We have not seen how to achieve this as regards
101 changes in header files, but we have achieved it as regards
102 changes in the actual functions of the Library.) The hope is
103 that this will lead to faster development of free libraries.
104
105 The precise terms and conditions for copying, distribution and
106 modification follow. Pay close attention to the difference
107 between a "work based on the library" and a "work that uses the
108 library". The former contains code derived from the library,
109 while the latter only works together with the library.
110
111 Note that it is possible for a library to be covered by the
112 ordinary General Public License rather than by this special one.
113
114 GNU LIBRARY GENERAL PUBLIC LICENSE
115 TERMS AND CONDITIONS FOR COPYING, DISTRIBUTION AND MODIFICATION
116
117 0. This License Agreement applies to any software library which
118 contains a notice placed by the copyright holder or other
119 authorized party saying it may be distributed under the terms of
120 this Library General Public License (also called "this
121 License"). Each licensee is addressed as "you".
122
123 A "library" means a collection of software functions and/or data
124 prepared so as to be conveniently linked with application
125 programs (which use some of those functions and data) to form
126 executables.
127
128 The "Library", below, refers to any such software library or
129 work which has been distributed under these terms. A "work
130 based on the Library" means either the Library or any derivative
131 work under copyright law: that is to say, a work containing the
132 Library or a portion of it, either verbatim or with
133 modifications and/or translated straightforwardly into another
134 language. (Hereinafter, translation is included without
135 limitation in the term "modification".)
136
137 "Source code" for a work means the preferred form of the work
138 for making modifications to it. For a library, complete source
139 code means all the source code for all modules it contains, plus
140 any associated interface definition files, plus the scripts used
141 to control compilation and installation of the library.
142
143 Activities other than copying, distribution and modification are
144 not covered by this License; they are outside its scope. The
145 act of running a program using the Library is not restricted,
146 and output from such a program is covered only if its contents
147 constitute a work based on the Library (independent of the use
148 of the Library in a tool for writing it). Whether that is true
149 depends on what the Library does and what the program that uses
150 the Library does.
151
152 1. You may copy and distribute verbatim copies of the Library's
153 complete source code as you receive it, in any medium, provided
154 that you conspicuously and appropriately publish on each copy an
155 appropriate copyright notice and disclaimer of warranty; keep
156 intact all the notices that refer to this License and to the
157 absence of any warranty; and distribute a copy of this License
158 along with the Library.
159
160 You may charge a fee for the physical act of transferring a
161 copy, and you may at your option offer warranty protection in
162 exchange for a fee.
163
164 2. You may modify your copy or copies of the Library or any
165 portion of it, thus forming a work based on the Library, and
166 copy and distribute such modifications or work under the terms
167 of Section 1 above, provided that you also meet all of these
168 conditions:
169
170 a) The modified work must itself be a software library.
171
172 b) You must cause the files modified to carry prominent notices
173 stating that you changed the files and the date of any change.
174
175 c) You must cause the whole of the work to be licensed at no
176 charge to all third parties under the terms of this License.
177
178 d) If a facility in the modified Library refers to a function or a
179 table of data to be supplied by an application program that uses
180 the facility, other than as an argument passed when the facility
181 is invoked, then you must make a good faith effort to ensure that,
182 in the event an application does not supply such function or
183 table, the facility still operates, and performs whatever part of
184 its purpose remains meaningful.
185
186 (For example, a function in a library to compute square roots has
187 a purpose that is entirely well-defined independent of the
188 application. Therefore, Subsection 2d requires that any
189 application-supplied function or table used by this function must
190 be optional: if the application does not supply it, the square
191 root function must still compute square roots.)
192
193 These requirements apply to the modified work as a whole. If
194 identifiable sections of that work are not derived from the
195 Library, and can be reasonably considered independent and
196 separate works in themselves, then this License, and its terms,
197 do not apply to those sections when you distribute them as
198 separate works. But when you distribute the same sections as
199 part of a whole which is a work based on the Library, the
200 distribution of the whole must be on the terms of this License,
201 whose permissions for other licensees extend to the entire
202 whole, and thus to each and every part regardless of who wrote
203 it.
204
205 Thus, it is not the intent of this section to claim rights or
206 contest your rights to work written entirely by you; rather, the
207 intent is to exercise the right to control the distribution of
208 derivative or collective works based on the Library.
209
210 In addition, mere aggregation of another work not based on the
211 Library with the Library (or with a work based on the Library)
212 on a volume of a storage or distribution medium does not bring
213 the other work under the scope of this License.
214
215 3. You may opt to apply the terms of the ordinary GNU General
216 Public License instead of this License to a given copy of the
217 Library. To do this, you must alter all the notices that refer
218 to this License, so that they refer to the ordinary GNU General
219 Public License, version 2, instead of to this License. (If a
220 newer version than version 2 of the ordinary GNU General Public
221 License has appeared, then you can specify that version instead
222 if you wish.) Do not make any other change in these notices.
223
224 Once this change is made in a given copy, it is irreversible for
225 that copy, so the ordinary GNU General Public License applies to
226 all subsequent copies and derivative works made from that copy.
227
228 This option is useful when you wish to copy part of the code of
229 the Library into a program that is not a library.
230
231 4. You may copy and distribute the Library (or a portion or
232 derivative of it, under Section 2) in object code or executable
233 form under the terms of Sections 1 and 2 above provided that you
234 accompany it with the complete corresponding machine-readable
235 source code, which must be distributed under the terms of
236 Sections 1 and 2 above on a medium customarily used for software
237 interchange.
238
239 If distribution of object code is made by offering access to
240 copy from a designated place, then offering equivalent access to
241 copy the source code from the same place satisfies the
242 requirement to distribute the source code, even though third
243 parties are not compelled to copy the source along with the
244 object code.
245
246 5. A program that contains no derivative of any portion of the
247 Library, but is designed to work with the Library by being
248 compiled or linked with it, is called a "work that uses the
249 Library". Such a work, in isolation, is not a derivative work
250 of the Library, and therefore falls outside the scope of this
251 License.
252
253 However, linking a "work that uses the Library" with the Library
254 creates an executable that is a derivative of the Library
255 (because it contains portions of the Library), rather than a
256 "work that uses the library". The executable is therefore
257 covered by this License. Section 6 states terms for distribution
258 of such executables.
259
260 When a "work that uses the Library" uses material from a header
261 file that is part of the Library, the object code for the work
262 may be a derivative work of the Library even though the source
263 code is not. Whether this is true is especially significant if
264 the work can be linked without the Library, or if the work is
265 itself a library. The threshold for this to be true is not
266 precisely defined by law.
267
268 If such an object file uses only numerical parameters, data
269 structure layouts and accessors, and small macros and small
270 inline functions (ten lines or less in length), then the use of
271 the object file is unrestricted, regardless of whether it is
272 legally a derivative work. (Executables containing this object
273 code plus portions of the Library will still fall under Section
274 6.)
275
276 Otherwise, if the work is a derivative of the Library, you may
277 distribute the object code for the work under the terms of
278 Section 6. Any executables containing that work also fall under
279 Section 6, whether or not they are linked directly with the
280 Library itself.
281
282 6. As an exception to the Sections above, you may also compile
283 or link a "work that uses the Library" with the Library to
284 produce a work containing portions of the Library, and
285 distribute that work under terms of your choice, provided that
286 the terms permit modification of the work for the customer's own
287 use and reverse engineering for debugging such modifications.
288
289 You must give prominent notice with each copy of the work that
290 the Library is used in it and that the Library and its use are
291 covered by this License. You must supply a copy of this
292 License. If the work during execution displays copyright
293 notices, you must include the copyright notice for the Library
294 among them, as well as a reference directing the user to the
295 copy of this License. Also, you must do one of these things:
296
297 a) Accompany the work with the complete corresponding
298 machine-readable source code for the Library including whatever
299 changes were used in the work (which must be distributed under
300 Sections 1 and 2 above); and, if the work is an executable linked
301 with the Library, with the complete machine-readable "work that
302 uses the Library", as object code and/or source code, so that the
303 user can modify the Library and then relink to produce a modified
304 executable containing the modified Library. (It is understood
305 that the user who changes the contents of definitions files in the
306 Library will not necessarily be able to recompile the application
307 to use the modified definitions.)
308
309 b) Accompany the work with a written offer, valid for at
310 least three years, to give the same user the materials
311 specified in Subsection 6a, above, for a charge no more
312 than the cost of performing this distribution.
313
314 c) If distribution of the work is made by offering access to copy
315 from a designated place, offer equivalent access to copy the above
316 specified materials from the same place.
317
318 d) Verify that the user has already received a copy of these
319 materials or that you have already sent this user a copy.
320
321 For an executable, the required form of the "work that uses the
322 Library" must include any data and utility programs needed for
323 reproducing the executable from it. However, as a special
324 exception, the source code distributed need not include anything
325 that is normally distributed (in either source or binary form)
326 with the major components (compiler, kernel, and so on) of the
327 operating system on which the executable runs, unless that
328 component itself accompanies the executable.
329
330 It may happen that this requirement contradicts the license
331 restrictions of other proprietary libraries that do not normally
332 accompany the operating system. Such a contradiction means you
333 cannot use both them and the Library together in an executable
334 that you distribute.
335
336 7. You may place library facilities that are a work based on the
337 Library side-by-side in a single library together with other
338 library facilities not covered by this License, and distribute
339 such a combined library, provided that the separate distribution
340 of the work based on the Library and of the other library
341 facilities is otherwise permitted, and provided that you do
342 these two things:
343
344 a) Accompany the combined library with a copy of the same work
345 based on the Library, uncombined with any other library
346 facilities. This must be distributed under the terms of the
347 Sections above.
348
349 b) Give prominent notice with the combined library of the fact
350 that part of it is a work based on the Library, and explaining
351 where to find the accompanying uncombined form of the same work.
352
353 8. You may not copy, modify, sublicense, link with, or
354 distribute the Library except as expressly provided under this
355 License. Any attempt otherwise to copy, modify, sublicense,
356 link with, or distribute the Library is void, and will
357 automatically terminate your rights under this License.
358 However, parties who have received copies, or rights, from you
359 under this License will not have their licenses terminated so
360 long as such parties remain in full compliance.
361
362 9. You are not required to accept this License, since you have
363 not signed it. However, nothing else grants you permission to
364 modify or distribute the Library or its derivative works. These
365 actions are prohibited by law if you do not accept this
366 License. Therefore, by modifying or distributing the Library
367 (or any work based on the Library), you indicate your acceptance
368 of this License to do so, and all its terms and conditions for
369 copying, distributing or modifying the Library or works based on
370 it.
371
372 10. Each time you redistribute the Library (or any work based on
373 the Library), the recipient automatically receives a license
374 from the original licensor to copy, distribute, link with or
375 modify the Library subject to these terms and conditions. You
376 may not impose any further restrictions on the recipients'
377 exercise of the rights granted herein. You are not responsible
378 for enforcing compliance by third parties to this License.
379
380 11. If, as a consequence of a court judgment or allegation of
381 patent infringement or for any other reason (not limited to
382 patent issues), conditions are imposed on you (whether by court
383 order, agreement or otherwise) that contradict the conditions of
384 this License, they do not excuse you from the conditions of this
385 License. If you cannot distribute so as to satisfy
386 simultaneously your obligations under this License and any other
387 pertinent obligations, then as a consequence you may not
388 distribute the Library at all. For example, if a patent license
389 would not permit royalty-free redistribution of the Library by
390 all those who receive copies directly or indirectly through you,
391 then the only way you could satisfy both it and this License
392 would be to refrain entirely from distribution of the Library.
393
394 If any portion of this section is held invalid or unenforceable
395 under any particular circumstance, the balance of the section is
396 intended to apply, and the section as a whole is intended to
397 apply in other circumstances.
398
399 It is not the purpose of this section to induce you to infringe
400 any patents or other property right claims or to contest
401 validity of any such claims; this section has the sole purpose
402 of protecting the integrity of the free software distribution
403 system which is implemented by public license practices. Many
404 people have made generous contributions to the wide range of
405 software distributed through that system in reliance on
406 consistent application of that system; it is up to the
407 author/donor to decide if he or she is willing to distribute
408 software through any other system and a licensee cannot impose
409 that choice.
410
411 This section is intended to make thoroughly clear what is
412 believed to be a consequence of the rest of this License.
413
414 12. If the distribution and/or use of the Library is restricted
415 in certain countries either by patents or by copyrighted
416 interfaces, the original copyright holder who places the Library
417 under this License may add an explicit geographical distribution
418 limitation excluding those countries, so that distribution is
419 permitted only in or among countries not thus excluded. In such
420 case, this License incorporates the limitation as if written in
421 the body of this License.
422
423 13. The Free Software Foundation may publish revised and/or new
424 versions of the Library General Public License from time to
425 time. Such new versions will be similar in spirit to the present
426 version, but may differ in detail to address new problems or
427 concerns.
428
429 Each version is given a distinguishing version number. If the
430 Library specifies a version number of this License which applies
431 to it and "any later version", you have the option of following
432 the terms and conditions either of that version or of any later
433 version published by the Free Software Foundation. If the
434 Library does not specify a license version number, you may
435 choose any version ever published by the Free Software
436 Foundation.
437
438 14. If you wish to incorporate parts of the Library into other
439 free programs whose distribution conditions are incompatible
440 with these, write to the author to ask for permission. For
441 software which is copyrighted by the Free Software Foundation,
442 write to the Free Software Foundation; we sometimes make
443 exceptions for this. Our decision will be guided by the two
444 goals of preserving the free status of all derivatives of our
445 free software and of promoting the sharing and reuse of software
446 generally.
447
448 NO WARRANTY
449
450 15. BECAUSE THE LIBRARY IS LICENSED FREE OF CHARGE, THERE IS NO
451 WARRANTY FOR THE LIBRARY, TO THE EXTENT PERMITTED BY APPLICABLE LAW.
452 EXCEPT WHEN OTHERWISE STATED IN WRITING THE COPYRIGHT HOLDERS AND/OR
453 OTHER PARTIES PROVIDE THE LIBRARY "AS IS" WITHOUT WARRANTY OF ANY KIND,
454 EITHER EXPRESSED OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, THE
455 IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
456 PURPOSE. THE ENTIRE RISK AS TO THE QUALITY AND PERFORMANCE OF THE
457 LIBRARY IS WITH YOU. SHOULD THE LIBRARY PROVE DEFECTIVE, YOU ASSUME
458 THE COST OF ALL NECESSARY SERVICING, REPAIR OR CORRECTION.
459
460 16. IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN
461 WRITING WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MAY MODIFY
462 AND/OR REDISTRIBUTE THE LIBRARY AS PERMITTED ABOVE, BE LIABLE TO YOU
463 FOR DAMAGES, INCLUDING ANY GENERAL, SPECIAL, INCIDENTAL OR CONSEQUENTIAL
464 DAMAGES ARISING OUT OF THE USE OR INABILITY TO USE THE
465 LIBRARY (INCLUDING BUT NOT LIMITED TO LOSS OF DATA OR DATA BEING
466 RENDERED INACCURATE OR LOSSES SUSTAINED BY YOU OR THIRD PARTIES OR A
467 FAILURE OF THE LIBRARY TO OPERATE WITH ANY OTHER SOFTWARE), EVEN IF
468 SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES.
469
470 END OF TERMS AND CONDITIONS
471
472 Appendix: How to Apply These Terms to Your New Libraries
473
474 If you develop a new library, and you want it to be of the
475 greatest possible use to the public, we recommend making it free
476 software that everyone can redistribute and change. You can do
477 so by permitting redistribution under these terms (or,
478 alternatively, under the terms of the ordinary General Public
479 License).
480
481 To apply these terms, attach the following notices to the
482 library. It is safest to attach them to the start of each
483 source file to most effectively convey the exclusion of
484 warranty; and each file should have at least the "copyright"
485 line and a pointer to where the full notice is found.
486
487 <one line to give the library's name and a brief idea of what it does.>
488 Copyright (C) <year> <name of author>
489
490 This library is free software; you can redistribute it and/or
491 modify it under the terms of the GNU Library General Public
492 License as published by the Free Software Foundation; either
493 version 2 of the License, or (at your option) any later version.
494
495 This library is distributed in the hope that it will be useful,
496 but WITHOUT ANY WARRANTY; without even the implied warranty of
497 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
498 Library General Public License for more details.
499
500 You should have received a copy of the GNU Library General Public
501 License along with this library; if not, write to the Free
502 Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
503
504 Also add information on how to contact you by electronic and paper mail.
505
506 You should also get your employer (if you work as a programmer) or your
507 school, if any, to sign a "copyright disclaimer" for the library, if
508 necessary. Here is a sample; alter the names:
509
510 Yoyodyne, Inc., hereby disclaims all copyright interest in the
511 library `Frob' (a library for tweaking knobs) written by James Random Hacker.
512
513 <signature of Ty Coon>, 1 April 1990
514 Ty Coon, President of Vice
515
516 That's all there is to it!
517