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      1 @node Library Copying
      2 @appendixsec GNU LESSER GENERAL PUBLIC LICENSE
      3 
      4 @cindex LGPL, Lesser General Public License
      5 @center Version 2.1, February 1999
      6 
      7 @display
      8 Copyright @copyright{} 1991, 1999 Free Software Foundation, Inc.
      9 51 Franklin Street - Fifth Floor, Boston, MA 02110-1301, USA
     10 
     11 Everyone is permitted to copy and distribute verbatim copies
     12 of this license document, but changing it is not allowed.
     13 
     14 [This is the first released version of the Lesser GPL.  It also counts
     15 as the successor of the GNU Library Public License, version 2, hence the
     16 version number 2.1.]
     17 @end display
     18 
     19 @appendixsubsec Preamble
     20 
     21   The licenses for most software are designed to take away your
     22 freedom to share and change it.  By contrast, the GNU General Public
     23 Licenses are intended to guarantee your freedom to share and change
     24 free software---to make sure the software is free for all its users.
     25 
     26   This license, the Lesser General Public License, applies to some
     27 specially designated software---typically libraries---of the Free
     28 Software Foundation and other authors who decide to use it.  You can use
     29 it too, but we suggest you first think carefully about whether this
     30 license or the ordinary General Public License is the better strategy to
     31 use in any particular case, based on the explanations below.
     32 
     33   When we speak of free software, we are referring to freedom of use,
     34 not price.  Our General Public Licenses are designed to make sure that
     35 you have the freedom to distribute copies of free software (and charge
     36 for this service if you wish); that you receive source code or can get
     37 it if you want it; that you can change the software and use pieces of it
     38 in new free programs; and that you are informed that you can do these
     39 things.
     40 
     41   To protect your rights, we need to make restrictions that forbid
     42 distributors to deny you these rights or to ask you to surrender these
     43 rights.  These restrictions translate to certain responsibilities for
     44 you 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
     47 or for a fee, you must give the recipients all the rights that we gave
     48 you.  You must make sure that they, too, receive or can get the source
     49 code.  If you link other code with the library, you must provide
     50 complete object files to the recipients, so that they can relink them
     51 with the library after making changes to the library and recompiling
     52 it.  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
     55 library, and (2) we offer you this license, which gives you legal
     56 permission to copy, distribute and/or modify the library.
     57 
     58   To protect each distributor, we want to make it very clear that
     59 there is no warranty for the free library.  Also, if the library is
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     64 
     65   Finally, software patents pose a constant threat to the existence of
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     71 
     72   Most GNU software, including some libraries, is covered by the
     73 ordinary GNU General Public License.  This license, the GNU Lesser
     74 General Public License, applies to certain designated libraries, and
     75 is quite different from the ordinary General Public License.  We use
     76 this license for certain libraries in order to permit linking those
     77 libraries into non-free programs.
     78 
     79   When a program is linked with a library, whether statically or using
     80 a shared library, the combination of the two is legally speaking a
     81 combined work, a derivative of the original library.  The ordinary
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     83 entire combination fits its criteria of freedom.  The Lesser General
     84 Public License permits more lax criteria for linking other code with
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     86 
     87   We call this license the @dfn{Lesser} General Public License because it
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     91 are the reason we use the ordinary General Public License for many
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     93 special circumstances.
     94 
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     99 library does the same job as widely used non-free libraries.  In this
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    109 
    110   Although the Lesser General Public License is Less protective of the
    111 users' freedom, it does ensure that the user of a program that is
    112 linked with the Library has the freedom and the wherewithal to run
    113 that program using a modified version of the Library.
    114 
    115   The precise terms and conditions for copying, distribution and
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    117 ``work based on the library'' and a ``work that uses the library''.  The
    118 former contains code derived from the library, whereas the latter must
    119 be combined with the library in order to run.
    120 
    121 @iftex
    122 @appendixsubsec TERMS AND CONDITIONS FOR COPYING, DISTRIBUTION AND MODIFICATION
    123 @end iftex
    124 @ifinfo
    125 @center GNU LESSER GENERAL PUBLIC LICENSE
    126 @center TERMS AND CONDITIONS FOR COPYING, DISTRIBUTION AND MODIFICATION
    127 @end ifinfo
    128 
    129 @enumerate 0
    130 @item
    131 This License Agreement applies to any software library or other program
    132 which contains a notice placed by the copyright holder or other
    133 authorized party saying it may be distributed under the terms of this
    134 Lesser General Public License (also called ``this License'').  Each
    135 licensee is addressed as ``you''.
    136 
    137   A ``library'' means a collection of software functions and/or data
    138 prepared so as to be conveniently linked with application programs
    139 (which use some of those functions and data) to form executables.
    140 
    141   The ``Library'', below, refers to any such software library or work
    142 which has been distributed under these terms.  A ``work based on the
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    150 making modifications to it.  For a library, complete source code means
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    154 
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    187 You must cause the files modified to carry prominent notices
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    195 If a facility in the modified Library refers to a function or a
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    200 table, the facility still operates, and performs whatever part of
    201 its purpose remains meaningful.
    202 
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    204 a purpose that is entirely well-defined independent of the
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    210 
    211 These requirements apply to the modified work as a whole.  If
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    233 You may opt to apply the terms of the ordinary GNU General Public
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    249 @item
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    311 @enumerate a
    312 @item
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    373 @enumerate a
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    384 @end enumerate
    385 
    386 @item
    387 You may not copy, modify, sublicense, link with, or distribute
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    415 If, as a consequence of a court judgment or allegation of patent
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    443 This section is intended to make thoroughly clear what is believed to
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    447 If the distribution and/or use of the Library is restricted in
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    455 @item
    456 The Free Software Foundation may publish revised and/or new
    457 versions of the Lesser General Public License from time to time.
    458 Such new versions will be similar in spirit to the present version,
    459 but may differ in detail to address new problems or concerns.
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    462 specifies a version number of this License which applies to it and
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    464 conditions either of that version or of any later version published by
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    470 If you wish to incorporate parts of the Library into other free
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    478 
    479 @center NO WARRANTY
    480 
    481 @item
    482 BECAUSE THE LIBRARY IS LICENSED FREE OF CHARGE, THERE IS NO
    483 WARRANTY FOR THE LIBRARY, TO THE EXTENT PERMITTED BY APPLICABLE LAW.
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    493 IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN
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    503 @end enumerate
    504 
    505 @iftex
    506 @heading END OF TERMS AND CONDITIONS
    507 @end iftex
    508 @ifinfo
    509 @center END OF TERMS AND CONDITIONS
    510 @end ifinfo
    511 
    512 @page
    513 @appendixsubsec How to Apply These Terms to Your New Libraries
    514 
    515   If you develop a new library, and you want it to be of the greatest
    516 possible use to the public, we recommend making it free software that
    517 everyone can redistribute and change.  You can do so by permitting
    518 redistribution under these terms (or, alternatively, under the terms of the
    519 ordinary General Public License).
    520 
    521   To apply these terms, attach the following notices to the library.  It is
    522 safest to attach them to the start of each source file to most effectively
    523 convey the exclusion of warranty; and each file should have at least the
    524 ``copyright'' line and a pointer to where the full notice is found.
    525 
    526 @smallexample
    527 @var{one line to give the library's name and an idea of what it does.}
    528 Copyright (C) @var{year}  @var{name of author}
    529 
    530 This library is free software; you can redistribute it and/or modify it
    531 under the terms of the GNU Lesser General Public License as published by
    532 the Free Software Foundation; either version 2.1 of the License, or (at
    533 your option) any later version.
    534 
    535 This library is distributed in the hope that it will be useful, but
    536 WITHOUT ANY WARRANTY; without even the implied warranty of
    537 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
    538 Lesser General Public License for more details.
    539 
    540 You should have received a copy of the GNU Lesser General Public
    541 License along with this library; if not, write to the Free Software
    542 Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
    543 USA.
    544 @end smallexample
    545 
    546 Also add information on how to contact you by electronic and paper mail.
    547 
    548 You should also get your employer (if you work as a programmer) or your
    549 school, if any, to sign a ``copyright disclaimer'' for the library, if
    550 necessary.  Here is a sample; alter the names:
    551 
    552 @smallexample
    553 Yoyodyne, Inc., hereby disclaims all copyright interest in the library
    554 `Frob' (a library for tweaking knobs) written by James Random Hacker.
    555 
    556 @var{signature of Ty Coon}, 1 April 1990
    557 Ty Coon, President of Vice
    558 @end smallexample
    559 
    560 That's all there is to it!
    561