\chapter{GNU Lesser General Public License}
\label{blbLesserChapter}
\index[general]{GNU Lesser General Public License }
\index[general]{License!GNU Lesser General Public }
\bref{\includegraphics{philosophical-gnu-sm}}
{http://www.gnu.org/graphics/philosophicalgnu.html}
[ \bref{English}{http://www.gnu.org/copyleft/lesser.html} |
\bref{Japanese}{http://www.gnu.org/copyleft/lesser.ja.html} ]

\begin{bitemize}
\item
   \bref{Why you shouldn't use the Lesser GPL for your next
   library}{http://www.gnu.org/philosophy/why-not-lgpl.html}
\item
   \bref{What to do if you see a possible LGPL
   violation}{http://www.gnu.org/copyleft/gpl-violation.html}
\item
   \bref{Translations of the LGPL}
{http://www.gnu.org/copyleft/copyleft.html\#translationsLGPL}
\item The GNU Lesser General Public License as a
   \bref{text file}{http://www.gnu.org/copyleft/lesser.txt}
\item The GNU Lesser General Public License as a
   \bref{Texinfo}{http://www.gnu.org/copyleft/lesser.texi} file
   \end{bitemize}


This GNU Lesser General Public License counts as the successor of the GNU
Library General Public License. For an explanation of why this change was
necessary, read the
\bref{Why you shouldn't use the Lesser GPL for your next
library}{http://www.gnu.org/philosophy/why-not-lgpl.html} article.

%\section{Table of Contents}
\minitoc
\index[general]{Table of Contents }
\index[general]{Contents!Table of }

%% \begin{bitemize}
%% \item
%%    \label{blbTOC12}
%%    \bilink{GNU LESSER GENERAL PUBLIC LICENSE}{blbSEC12}

%% \begin{bitemize}
%% \item
%%    \label{blbTOC23}
%%    \bilink{Preamble}{blbSEC23}
%% \item
%%    \label{blbTOC34}
%%    \bilink{TERMS AND CONDITIONS FOR COPYING, DISTRIBUTION AND
%% MODIFICATION}{blbSEC34}
%% \item
%%    \label{blbTOC45}
%%    \bilink{How to Apply These Terms to Your New Libraries}{blbSEC45}
%% \end{bitemize}

%% \end{bitemize}


\section{GNU LESSER GENERAL PUBLIC LICENSE}
\label{blbSEC12}
\index[general]{LICENSE!GNU LESSER GENERAL PUBLIC }
\index[general]{GNU LESSER GENERAL PUBLIC LICENSE }

Version 2.1, February 1999

\begin{bVerbatim}
Copyright (C) 1991, 1999 Free Software Foundation, Inc.
51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
Everyone is permitted to copy and distribute bVerbatim copies
of this license document, but changing it is not allowed.
[This is the first released version of the Lesser GPL.  It also counts
 as the successor of the GNU Library Public License, version 2, hence
 the version number 2.1.]
\end{bVerbatim}

\section{Preamble}
\label{blbSEC23}
\index[general]{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 Lesser General Public License, applies to some specially
designated software packages --- typically libraries --- of the Free Software
Foundation and other authors who decide to use it. You can use it too, but we
suggest you first think carefully about whether this license or the ordinary
General Public License is the better strategy to use in any particular case,
based on the explanations below.

When we speak of free software, we are referring to freedom of use, not price.
Our General Public Licenses are designed to make sure that you have the
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To protect your rights, we need to make restrictions that forbid distributors
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For example, if you distribute copies of the library, whether gratis or for a
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We protect your rights with a two-step method: (1) we copyright the library,
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To protect each distributor, we want to make it very clear that there is no
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Most GNU software, including some libraries, is covered by the ordinary GNU
General Public License. This license, the GNU Lesser General Public License,
applies to certain designated libraries, and is quite different from the
ordinary General Public License. We use this license for certain libraries in
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When a program is linked with a library, whether statically or using a shared
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therefore permits such linking only if the entire combination fits its
criteria of freedom. The Lesser General Public License permits more lax
criteria for linking other code with the library.

We call this license the "Lesser" General Public License because it does
Less to protect the user's freedom than the ordinary General Public License.
It also provides other free software developers Less of an advantage over
competing non-free programs. These disadvantages are the reason we use the
ordinary General Public License for many libraries. However, the Lesser
license provides advantages in certain special circumstances.

For example, on rare occasions, there may be a special need to encourage the
widest possible use of a certain library, so that it becomes a de-facto
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Public License.

In other cases, permission to use a particular library in non-free programs
enables a greater number of people to use a large body of free software. For
example, permission to use the GNU C Library in non-free programs enables many
more people to use the whole GNU operating system, as well as its variant, the
GNU/Linux operating system.

Although the Lesser General Public License is Less protective of the users'
freedom, it does ensure that the user of a program that is linked with the
Library has the freedom and the wherewithal to run that program using a
modified version of the Library.

The precise terms and conditions for copying, distribution and modification
follow. Pay close attention to the difference between a "work based on the
library" and a "work that uses the library". The former contains code
derived from the library, whereas the latter must be combined with the library
in order to run.

\section{TERMS AND CONDITIONS}
\label{blbSEC34}
\index[general]{CONDITIONS!TERMS AND }
\index[general]{TERMS AND CONDITIONS }

TERMS AND CONDITIONS FOR COPYING, DISTRIBUTION AND MODIFICATION

{\bf 0.} This License Agreement applies to any software library or other
program which contains a notice placed by the copyright holder or other
authorized party saying it may be distributed under the terms of this Lesser
General Public License (also called "this License"). Each licensee is
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A "library" means a collection of software functions and/or data prepared so
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{\bf 1.} You may copy and distribute bVerbatim copies of the Library's complete
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\begin{bitemize}
\item {\bf a)}  The modified work must itself be a software library.
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\end{bitemize}

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\begin{bitemize}
\item {\bf a)} Accompany the work with the complete corresponding
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and, if the work is an executable linked  with the Library, with the complete
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\item {\bf c)} Accompany the work with a written offer, valid for at  least
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{\bf 7.} You may place library facilities that are a work based on the Library
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\begin{bitemize}
\item {\bf a)} Accompany the combined library with a copy of the same work
   based on the Library, uncombined with any other library  facilities. This must
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{\bf 8.} You may not copy, modify, sublicense, link with, or distribute the
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If any portion of this section is held invalid or unenforceable under any
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It is not the purpose of this section to induce you to infringe any patents or
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{\bf 12.} If the distribution and/or use of the Library is restricted in
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{\bf 13.} The Free Software Foundation may publish revised and/or new versions
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Each version is given a distinguishing version number. If the Library
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{\bf NO WARRANTY}

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END OF TERMS AND CONDITIONS

\section{How to Apply These Terms to Your New Libraries}
\label{blbSEC45}
\index[general]{Libraries!How to Apply These Terms to Your New }
\index[general]{How to Apply These Terms to Your New Libraries }


If you develop a new library, and you want it to be of the greatest possible
use to the public, we recommend making it free software that everyone can
redistribute and change. You can do so by permitting redistribution under
these terms (or, alternatively, under the terms of the ordinary General Public
License).

To apply these terms, attach the following notices to the library. It is
safest to attach them to the start of each source file to most effectively
convey the exclusion of warranty; and each file should have at least the
"copyright" line and a pointer to where the full notice is found.

\begin{bVerbatim}
{\it one line to give the library's name and an idea of what it does.}
Copyright (C) {\it year}  {\it name of author}
This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
This library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with this library; if not, write to the Free Software
Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301
USA
\end{bVerbatim}

Also add information on how to contact you by electronic and paper mail.

You should also get your employer (if you work as a programmer) or your
school, if any, to sign a "copyright disclaimer" for the library, if
necessary. Here is a sample; alter the names:

\begin{bVerbatim}
Yoyodyne, Inc., hereby disclaims all copyright interest in
the library "Frob" (a library for tweaking knobs) written
by James Random Hacker.
{\it signature of Ty Coon}, 1 April 1990
Ty Coon, President of Vice
\end{bVerbatim}

That's all there is to it!
Return to
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Boston, MA  02110-1301  USA
USA

Updated: 27 Nov 2000 paulv