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