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