[This is the first released version of the library GPL. It is numbered 2 because it goes with version 2 of the
ordinary GPL.]
Preamble
The licenses for most software are designed to take away your freedom to share and change it. By contrast,
the GNU General Public Licenses are intended to guarantee your freedom to share and change free
software--to make sure the software is free for all its users.
This license, the Library General Public License, applies to some specially designated Free Software
Foundation software, and to any other libraries whose authors decide to use it. You can use it for your
libraries, too.
When we speak of free software, we are referring to freedom, not price. Our General Public Licenses are
designed to make sure that you have the freedom to distribute copies of free software (and charge for this
service if you wish), that you receive source code or can get it if you want it, that you can change the software
or use pieces of it in new free programs; and that you know you can do these things.
To protect your rights, we need to make restrictions that forbid anyone to deny you these rights or to ask you
to surrender the rights. These restrictions translate to certain responsibilities for you if you distribute copies
of the library, or if you modify it.
For example, if you distribute copies of the library, whether gratis or for a fee, you must give the recipients all
the rights that we gave you. You must make sure that they, too, receive or can get the source code. If you link
a program with the library, you must provide complete object files to the recipients so that they can relink
them with the library, after making changes to the library and recompiling it. And you must show them these
terms so they know their rights.
Our method of protecting your rights has two steps: (1) copyright the library, and (2) offer you this license
which gives you legal permission to copy, distribute and/or modify the library.
Also, for each distributor's protection, we want to make certain that everyone understands that there is no
warranty for this free library. If the library is modified by someone else and passed on, we want its recipients
to know that what they have is not the original version, so that any problems introduced by others will not
reflect on the original authors' reputations.
Finally, any free program is threatened constantly by software patents. We wish to avoid the danger that
companies distributing free software will individually obtain patent licenses, thus in effect transforming the
program into 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 libraries. This license is quite different from the ordinary one; be sure to read it in full, and don't
assume that 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 program. However, in a textual and legal sense, the linked executable is a combined
work, a derivative of the 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 non-free programs to use free libraries, while preserving your freedom as a user of such
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APPENDIX > About third party software programs
