• Home
  • Line#
  • Scopes#
  • Navigate#
  • Raw
  • Download
1@c The GNU Lesser General Public License.
2@center Version 2.1, February 1999
3
4@c This file is intended to be included within another document,
5@c hence no sectioning command or @node.
6
7@display
8Copyright @copyright{} 1991, 1999 Free Software Foundation, Inc.
951 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA
10
11Everyone is permitted to copy and distribute verbatim copies
12of this license document, but changing it is not allowed.
13
14[This is the first released version of the Lesser GPL.  It also counts
15as the successor of the GNU Library Public License, version 2, hence the
16version number 2.1.]
17@end display
18
19@subheading Preamble
20
21  The licenses for most software are designed to take away your
22freedom to share and change it.  By contrast, the GNU General Public
23Licenses are intended to guarantee your freedom to share and change
24free software---to make sure the software is free for all its users.
25
26  This license, the Lesser General Public License, applies to some
27specially designated software---typically libraries---of the Free
28Software Foundation and other authors who decide to use it.  You can use
29it too, but we suggest you first think carefully about whether this
30license or the ordinary General Public License is the better strategy to
31use in any particular case, based on the explanations below.
32
33  When we speak of free software, we are referring to freedom of use,
34not price.  Our General Public Licenses are designed to make sure that
35you have the freedom to distribute copies of free software (and charge
36for this service if you wish); that you receive source code or can get
37it if you want it; that you can change the software and use pieces of it
38in new free programs; and that you are informed that you can do these
39things.
40
41  To protect your rights, we need to make restrictions that forbid
42distributors to deny you these rights or to ask you to surrender these
43rights.  These restrictions translate to certain responsibilities for
44you if you distribute copies of the library or if you modify it.
45
46  For example, if you distribute copies of the library, whether gratis
47or for a fee, you must give the recipients all the rights that we gave
48you.  You must make sure that they, too, receive or can get the source
49code.  If you link other code with the library, you must provide
50complete object files to the recipients, so that they can relink them
51with the library after making changes to the library and recompiling
52it.  And you must show them these terms so they know their rights.
53
54  We protect your rights with a two-step method: (1) we copyright the
55library, and (2) we offer you this license, which gives you legal
56permission to copy, distribute and/or modify the library.
57
58  To protect each distributor, we want to make it very clear that
59there is no warranty for the free library.  Also, if the library is
60modified by someone else and passed on, the recipients should know
61that what they have is not the original version, so that the original
62author's reputation will not be affected by problems that might be
63introduced by others.
64
65  Finally, software patents pose a constant threat to the existence of
66any free program.  We wish to make sure that a company cannot
67effectively restrict the users of a free program by obtaining a
68restrictive license from a patent holder.  Therefore, we insist that
69any patent license obtained for a version of the library must be
70consistent with the full freedom of use specified in this license.
71
72  Most GNU software, including some libraries, is covered by the
73ordinary GNU General Public License.  This license, the GNU Lesser
74General Public License, applies to certain designated libraries, and
75is quite different from the ordinary General Public License.  We use
76this license for certain libraries in order to permit linking those
77libraries into non-free programs.
78
79  When a program is linked with a library, whether statically or using
80a shared library, the combination of the two is legally speaking a
81combined work, a derivative of the original library.  The ordinary
82General Public License therefore permits such linking only if the
83entire combination fits its criteria of freedom.  The Lesser General
84Public License permits more lax criteria for linking other code with
85the library.
86
87  We call this license the @dfn{Lesser} General Public License because it
88does @emph{Less} to protect the user's freedom than the ordinary General
89Public License.  It also provides other free software developers Less
90of an advantage over competing non-free programs.  These disadvantages
91are the reason we use the ordinary General Public License for many
92libraries.  However, the Lesser license provides advantages in certain
93special circumstances.
94
95  For example, on rare occasions, there may be a special need to
96encourage the widest possible use of a certain library, so that it becomes
97a de-facto standard.  To achieve this, non-free programs must be
98allowed to use the library.  A more frequent case is that a free
99library does the same job as widely used non-free libraries.  In this
100case, there is little to gain by limiting the free library to free
101software only, so we use the Lesser General Public License.
102
103  In other cases, permission to use a particular library in non-free
104programs enables a greater number of people to use a large body of
105free software.  For example, permission to use the GNU C Library in
106non-free programs enables many more people to use the whole GNU
107operating system, as well as its variant, the GNU/Linux operating
108system.
109
110  Although the Lesser General Public License is Less protective of the
111users' freedom, it does ensure that the user of a program that is
112linked with the Library has the freedom and the wherewithal to run
113that program using a modified version of the Library.
114
115  The precise terms and conditions for copying, distribution and
116modification follow.  Pay close attention to the difference between a
117``work based on the library'' and a ``work that uses the library''.  The
118former contains code derived from the library, whereas the latter must
119be combined with the library in order to run.
120
121@subheading TERMS AND CONDITIONS FOR COPYING, DISTRIBUTION AND MODIFICATION
122
123@enumerate 0
124@item
125This License Agreement applies to any software library or other program
126which contains a notice placed by the copyright holder or other
127authorized party saying it may be distributed under the terms of this
128Lesser General Public License (also called ``this License'').  Each
129licensee is addressed as ``you''.
130
131  A ``library'' means a collection of software functions and/or data
132prepared so as to be conveniently linked with application programs
133(which use some of those functions and data) to form executables.
134
135  The ``Library'', below, refers to any such software library or work
136which has been distributed under these terms.  A ``work based on the
137Library'' means either the Library or any derivative work under
138copyright law: that is to say, a work containing the Library or a
139portion of it, either verbatim or with modifications and/or translated
140straightforwardly into another language.  (Hereinafter, translation is
141included without limitation in the term ``modification''.)
142
143  ``Source code'' for a work means the preferred form of the work for
144making modifications to it.  For a library, complete source code means
145all the source code for all modules it contains, plus any associated
146interface definition files, plus the scripts used to control compilation
147and installation of the library.
148
149  Activities other than copying, distribution and modification are not
150covered by this License; they are outside its scope.  The act of
151running a program using the Library is not restricted, and output from
152such a program is covered only if its contents constitute a work based
153on the Library (independent of the use of the Library in a tool for
154writing it).  Whether that is true depends on what the Library does
155and what the program that uses the Library does.
156
157@item
158You may copy and distribute verbatim copies of the Library's
159complete source code as you receive it, in any medium, provided that
160you conspicuously and appropriately publish on each copy an
161appropriate copyright notice and disclaimer of warranty; keep intact
162all the notices that refer to this License and to the absence of any
163warranty; and distribute a copy of this License along with the
164Library.
165
166  You may charge a fee for the physical act of transferring a copy,
167and you may at your option offer warranty protection in exchange for a
168fee.
169
170@item
171You may modify your copy or copies of the Library or any portion
172of it, thus forming a work based on the Library, and copy and
173distribute such modifications or work under the terms of Section 1
174above, provided that you also meet all of these conditions:
175
176@enumerate a
177@item
178The modified work must itself be a software library.
179
180@item
181You must cause the files modified to carry prominent notices
182stating that you changed the files and the date of any change.
183
184@item
185You must cause the whole of the work to be licensed at no
186charge to all third parties under the terms of this License.
187
188@item
189If a facility in the modified Library refers to a function or a
190table of data to be supplied by an application program that uses
191the facility, other than as an argument passed when the facility
192is invoked, then you must make a good faith effort to ensure that,
193in the event an application does not supply such function or
194table, the facility still operates, and performs whatever part of
195its purpose remains meaningful.
196
197(For example, a function in a library to compute square roots has
198a purpose that is entirely well-defined independent of the
199application.  Therefore, Subsection 2d requires that any
200application-supplied function or table used by this function must
201be optional: if the application does not supply it, the square
202root function must still compute square roots.)
203@end enumerate
204
205These requirements apply to the modified work as a whole.  If
206identifiable sections of that work are not derived from the Library,
207and can be reasonably considered independent and separate works in
208themselves, then this License, and its terms, do not apply to those
209sections when you distribute them as separate works.  But when you
210distribute the same sections as part of a whole which is a work based
211on the Library, the distribution of the whole must be on the terms of
212this License, whose permissions for other licensees extend to the
213entire whole, and thus to each and every part regardless of who wrote
214it.
215
216Thus, it is not the intent of this section to claim rights or contest
217your rights to work written entirely by you; rather, the intent is to
218exercise the right to control the distribution of derivative or
219collective works based on the Library.
220
221In addition, mere aggregation of another work not based on the Library
222with the Library (or with a work based on the Library) on a volume of
223a storage or distribution medium does not bring the other work under
224the scope of this License.
225
226@item
227You may opt to apply the terms of the ordinary GNU General Public
228License instead of this License to a given copy of the Library.  To do
229this, you must alter all the notices that refer to this License, so
230that they refer to the ordinary GNU General Public License, version 2,
231instead of to this License.  (If a newer version than version 2 of the
232ordinary GNU General Public License has appeared, then you can specify
233that version instead if you wish.)  Do not make any other change in
234these notices.
235
236  Once this change is made in a given copy, it is irreversible for
237that copy, so the ordinary GNU General Public License applies to all
238subsequent copies and derivative works made from that copy.
239
240  This option is useful when you wish to copy part of the code of
241the Library into a program that is not a library.
242
243@item
244You may copy and distribute the Library (or a portion or
245derivative of it, under Section 2) in object code or executable form
246under the terms of Sections 1 and 2 above provided that you accompany
247it with the complete corresponding machine-readable source code, which
248must be distributed under the terms of Sections 1 and 2 above on a
249medium customarily used for software interchange.
250
251  If distribution of object code is made by offering access to copy
252from a designated place, then offering equivalent access to copy the
253source code from the same place satisfies the requirement to
254distribute the source code, even though third parties are not
255compelled to copy the source along with the object code.
256
257@item
258A program that contains no derivative of any portion of the
259Library, but is designed to work with the Library by being compiled or
260linked with it, is called a ``work that uses the Library''.  Such a
261work, in isolation, is not a derivative work of the Library, and
262therefore falls outside the scope of this License.
263
264  However, linking a ``work that uses the Library'' with the Library
265creates an executable that is a derivative of the Library (because it
266contains portions of the Library), rather than a ``work that uses the
267library''.  The executable is therefore covered by this License.
268Section 6 states terms for distribution of such executables.
269
270  When a ``work that uses the Library'' uses material from a header file
271that is part of the Library, the object code for the work may be a
272derivative work of the Library even though the source code is not.
273Whether this is true is especially significant if the work can be
274linked without the Library, or if the work is itself a library.  The
275threshold for this to be true is not precisely defined by law.
276
277  If such an object file uses only numerical parameters, data
278structure layouts and accessors, and small macros and small inline
279functions (ten lines or less in length), then the use of the object
280file is unrestricted, regardless of whether it is legally a derivative
281work.  (Executables containing this object code plus portions of the
282Library will still fall under Section 6.)
283
284  Otherwise, if the work is a derivative of the Library, you may
285distribute the object code for the work under the terms of Section 6.
286Any executables containing that work also fall under Section 6,
287whether or not they are linked directly with the Library itself.
288
289@item
290As an exception to the Sections above, you may also combine or
291link a ``work that uses the Library'' with the Library to produce a
292work containing portions of the Library, and distribute that work
293under terms of your choice, provided that the terms permit
294modification of the work for the customer's own use and reverse
295engineering for debugging such modifications.
296
297  You must give prominent notice with each copy of the work that the
298Library is used in it and that the Library and its use are covered by
299this License.  You must supply a copy of this License.  If the work
300during execution displays copyright notices, you must include the
301copyright notice for the Library among them, as well as a reference
302directing the user to the copy of this License.  Also, you must do one
303of these things:
304
305@enumerate a
306@item
307Accompany the work with the complete corresponding
308machine-readable source code for the Library including whatever
309changes were used in the work (which must be distributed under
310Sections 1 and 2 above); and, if the work is an executable linked
311with the Library, with the complete machine-readable ``work that
312uses the Library'', as object code and/or source code, so that the
313user can modify the Library and then relink to produce a modified
314executable containing the modified Library.  (It is understood
315that the user who changes the contents of definitions files in the
316Library will not necessarily be able to recompile the application
317to use the modified definitions.)
318
319@item
320Use a suitable shared library mechanism for linking with the Library.  A
321suitable mechanism is one that (1) uses at run time a copy of the
322library already present on the user's computer system, rather than
323copying library functions into the executable, and (2) will operate
324properly with a modified version of the library, if the user installs
325one, as long as the modified version is interface-compatible with the
326version that the work was made with.
327
328@item
329Accompany the work with a written offer, valid for at
330least three years, to give the same user the materials
331specified in Subsection 6a, above, for a charge no more
332than the cost of performing this distribution.
333
334@item
335If distribution of the work is made by offering access to copy
336from a designated place, offer equivalent access to copy the above
337specified materials from the same place.
338
339@item
340Verify that the user has already received a copy of these
341materials or that you have already sent this user a copy.
342@end enumerate
343
344  For an executable, the required form of the ``work that uses the
345Library'' must include any data and utility programs needed for
346reproducing the executable from it.  However, as a special exception,
347the materials to be distributed need not include anything that is
348normally distributed (in either source or binary form) with the major
349components (compiler, kernel, and so on) of the operating system on
350which the executable runs, unless that component itself accompanies the
351executable.
352
353  It may happen that this requirement contradicts the license
354restrictions of other proprietary libraries that do not normally
355accompany the operating system.  Such a contradiction means you cannot
356use both them and the Library together in an executable that you
357distribute.
358
359@item
360You may place library facilities that are a work based on the
361Library side-by-side in a single library together with other library
362facilities not covered by this License, and distribute such a combined
363library, provided that the separate distribution of the work based on
364the Library and of the other library facilities is otherwise
365permitted, and provided that you do these two things:
366
367@enumerate a
368@item
369Accompany the combined library with a copy of the same work
370based on the Library, uncombined with any other library
371facilities.  This must be distributed under the terms of the
372Sections above.
373
374@item
375Give prominent notice with the combined library of the fact
376that part of it is a work based on the Library, and explaining
377where to find the accompanying uncombined form of the same work.
378@end enumerate
379
380@item
381You may not copy, modify, sublicense, link with, or distribute
382the Library except as expressly provided under this License.  Any
383attempt otherwise to copy, modify, sublicense, link with, or
384distribute the Library is void, and will automatically terminate your
385rights under this License.  However, parties who have received copies,
386or rights, from you under this License will not have their licenses
387terminated so long as such parties remain in full compliance.
388
389@item
390You are not required to accept this License, since you have not
391signed it.  However, nothing else grants you permission to modify or
392distribute the Library or its derivative works.  These actions are
393prohibited by law if you do not accept this License.  Therefore, by
394modifying or distributing the Library (or any work based on the
395Library), you indicate your acceptance of this License to do so, and
396all its terms and conditions for copying, distributing or modifying
397the Library or works based on it.
398
399@item
400Each time you redistribute the Library (or any work based on the
401Library), the recipient automatically receives a license from the
402original licensor to copy, distribute, link with or modify the Library
403subject to these terms and conditions.  You may not impose any further
404restrictions on the recipients' exercise of the rights granted herein.
405You are not responsible for enforcing compliance by third parties with
406this License.
407
408@item
409If, as a consequence of a court judgment or allegation of patent
410infringement or for any other reason (not limited to patent issues),
411conditions are imposed on you (whether by court order, agreement or
412otherwise) that contradict the conditions of this License, they do not
413excuse you from the conditions of this License.  If you cannot
414distribute so as to satisfy simultaneously your obligations under this
415License and any other pertinent obligations, then as a consequence you
416may not distribute the Library at all.  For example, if a patent
417license would not permit royalty-free redistribution of the Library by
418all those who receive copies directly or indirectly through you, then
419the only way you could satisfy both it and this License would be to
420refrain entirely from distribution of the Library.
421
422If any portion of this section is held invalid or unenforceable under any
423particular circumstance, the balance of the section is intended to apply,
424and the section as a whole is intended to apply in other circumstances.
425
426It is not the purpose of this section to induce you to infringe any
427patents or other property right claims or to contest validity of any
428such claims; this section has the sole purpose of protecting the
429integrity of the free software distribution system which is
430implemented by public license practices.  Many people have made
431generous contributions to the wide range of software distributed
432through that system in reliance on consistent application of that
433system; it is up to the author/donor to decide if he or she is willing
434to distribute software through any other system and a licensee cannot
435impose that choice.
436
437This section is intended to make thoroughly clear what is believed to
438be a consequence of the rest of this License.
439
440@item
441If the distribution and/or use of the Library is restricted in
442certain countries either by patents or by copyrighted interfaces, the
443original copyright holder who places the Library under this License may add
444an explicit geographical distribution limitation excluding those countries,
445so that distribution is permitted only in or among countries not thus
446excluded.  In such case, this License incorporates the limitation as if
447written in the body of this License.
448
449@item
450The Free Software Foundation may publish revised and/or new
451versions of the Lesser General Public License from time to time.
452Such new versions will be similar in spirit to the present version,
453but may differ in detail to address new problems or concerns.
454
455Each version is given a distinguishing version number.  If the Library
456specifies a version number of this License which applies to it and
457``any later version'', you have the option of following the terms and
458conditions either of that version or of any later version published by
459the Free Software Foundation.  If the Library does not specify a
460license version number, you may choose any version ever published by
461the Free Software Foundation.
462
463@item
464If you wish to incorporate parts of the Library into other free
465programs whose distribution conditions are incompatible with these,
466write to the author to ask for permission.  For software which is
467copyrighted by the Free Software Foundation, write to the Free
468Software Foundation; we sometimes make exceptions for this.  Our
469decision will be guided by the two goals of preserving the free status
470of all derivatives of our free software and of promoting the sharing
471and reuse of software generally.
472
473@center @b{NO WARRANTY}
474
475@item
476BECAUSE THE LIBRARY IS LICENSED FREE OF CHARGE, THERE IS NO
477WARRANTY FOR THE LIBRARY, TO THE EXTENT PERMITTED BY APPLICABLE LAW.
478EXCEPT WHEN OTHERWISE STATED IN WRITING THE COPYRIGHT HOLDERS AND/OR
479OTHER PARTIES PROVIDE THE LIBRARY ``AS IS'' WITHOUT WARRANTY OF ANY
480KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, THE
481IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
482PURPOSE.  THE ENTIRE RISK AS TO THE QUALITY AND PERFORMANCE OF THE
483LIBRARY IS WITH YOU.  SHOULD THE LIBRARY PROVE DEFECTIVE, YOU ASSUME
484THE COST OF ALL NECESSARY SERVICING, REPAIR OR CORRECTION.
485
486@item
487IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN
488WRITING WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MAY MODIFY
489AND/OR REDISTRIBUTE THE LIBRARY AS PERMITTED ABOVE, BE LIABLE TO YOU
490FOR DAMAGES, INCLUDING ANY GENERAL, SPECIAL, INCIDENTAL OR
491CONSEQUENTIAL DAMAGES ARISING OUT OF THE USE OR INABILITY TO USE THE
492LIBRARY (INCLUDING BUT NOT LIMITED TO LOSS OF DATA OR DATA BEING
493RENDERED INACCURATE OR LOSSES SUSTAINED BY YOU OR THIRD PARTIES OR A
494FAILURE OF THE LIBRARY TO OPERATE WITH ANY OTHER SOFTWARE), EVEN IF
495SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
496DAMAGES.
497@end enumerate
498
499@subheading END OF TERMS AND CONDITIONS
500
501@page
502@subheading How to Apply These Terms to Your New Libraries
503
504  If you develop a new library, and you want it to be of the greatest
505possible use to the public, we recommend making it free software that
506everyone can redistribute and change.  You can do so by permitting
507redistribution under these terms (or, alternatively, under the terms of the
508ordinary General Public License).
509
510  To apply these terms, attach the following notices to the library.  It is
511safest to attach them to the start of each source file to most effectively
512convey the exclusion of warranty; and each file should have at least the
513``copyright'' line and a pointer to where the full notice is found.
514
515@smallexample
516@var{one line to give the library's name and an idea of what it does.}
517Copyright (C) @var{year}  @var{name of author}
518
519This library is free software; you can redistribute it and/or modify it
520under the terms of the GNU Lesser General Public License as published by
521the Free Software Foundation; either version 2.1 of the License, or (at
522your option) any later version.
523
524This library is distributed in the hope that it will be useful, but
525WITHOUT ANY WARRANTY; without even the implied warranty of
526MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
527Lesser General Public License for more details.
528
529You should have received a copy of the GNU Lesser General Public
530License along with this library; if not, write to the Free Software
531Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
532USA.
533@end smallexample
534
535Also add information on how to contact you by electronic and paper mail.
536
537You should also get your employer (if you work as a programmer) or your
538school, if any, to sign a ``copyright disclaimer'' for the library, if
539necessary.  Here is a sample; alter the names:
540
541@smallexample
542Yoyodyne, Inc., hereby disclaims all copyright interest in the library
543`Frob' (a library for tweaking knobs) written by James Random Hacker.
544
545@var{signature of Ty Coon}, 1 April 1990
546Ty Coon, President of Vice
547@end smallexample
548
549That's all there is to it!
550