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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 programs to change the
free libraries that are incorporated in them. (We have not seen how to achieve this as
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