Release Notes

This is free software, and you are welcome to redistribute it
under certain conditions; type `show c' for details.
The hypothetical commands `show w' and `show c' should show the appropriate parts of the General Public License. Of course,
your program's commands might be different; for a GUI interface, you would use an “about box”.
You should also get your employer (if you work as a programmer) or school, if any, to sign a “copyright disclaimer” for the
program, if necessary. For more information on this, and how to apply and follow the GNU GPL, see <http://www.gnu.org/
licenses/>.
The GNU General Public License does not permit incorporating your program into proprietary programs. If your program is a
subroutine library, you may consider it more useful to permit linking proprietary applications with the library. If this is what you
want to do, use the GNU Lesser General Public License instead of this License. But first, please read <http://www.gnu.org/
philosophy/why-not-lgpl.html>.
GNU LIBRARY GENERAL PUBLIC LICENSE
Version 2, June 1991
Copyright (C) 1991 Free Software Foundation, Inc.
51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
Everyone is permitted to copy and distribute verbatim copies of this license document, but changing it is not allowed.
[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.
Third-party software
67