Finally, any free program is threatened constantly by software patents. We wish to avoid the danger that companies
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proprietary software. To prevent this, we have made it clear that any patent must be licensed for everyone's free
use or not licensed at all.
Most GNU software, including some libraries, is covered by the ordinary GNU General Public License, which was
designed for utility programs. This license, the GNU Library General Public License, applies to certain designated
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anything in it is the same as in the ordinary license.
The reason we have a separate public license for some libraries is that they blur the distinction we usually make
between modifying or adding to a program and simply using it. Linking a program with a library, without changing
the library, is in some sense simply using the library, and is analogous to running a utility program or application
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original library, and the ordinary General Public License treats it as such.
Because of this blurred distinction, using the ordinary General Public License for libraries did not effectively promote
software sharing, because most developers did not use the libraries. We concluded that weaker conditions might
promote sharing better.
However, unrestricted linking of non-free programs would deprive the users of those programs of all benefit from
the free status of the libraries themselves. This Library General Public License is intended to permit developers of
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The precise terms and conditions for copying, distribution and modification follow. Pay close attention to the
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Note that it is possible for a library to be covered by the ordinary General Public License rather than by this special
one.
GNU LIBRARY GENERAL PUBLIC LICENSE
TERMS AND CONDITIONS FOR COPYING, DISTRIBUTION AND MODIFICATION
0. This License Agreement applies to any software library which contains a notice placed by the copyright holder or
other authorized party saying it may be distributed under the terms of this Library General Public License (also
called "this License"). Each licensee is addressed as "you".
A "library" means a collection of software functions and/or data prepared so as to be conveniently linked with
application programs (which use some of those functions and data) to form executables.
The "Library", below, refers to any such software library or work which has been distributed under these terms. A
"work based on the Library" means either the Library or any derivative work under copyright law: that is to say, a
work containing the Library or a portion of it, either verbatim or with modifications and/or translated
straightforwardly into another language. (Hereinafter, translation is included without limitation in the term
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"Source code" for a work means the preferred form of the work for making modifications to it. For a library,
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