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 and use pieces of it in new free
programs; and that you are informed that you can do these things.
To protect your rights, we need to make restrictions that forbid distributors to deny you these rights or to ask you to
surrender these 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 other code 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.
We protect your rights with a two-step method: (1) we copyright the library, and (2) we offer you this license, which gives
you legal permission to copy, distribute and/or modify the library.
To protect each distributor, we want to make it very clear that there is no warranty for the free library. Also, if the library
is modified by someone else and passed on, the recipients should know that what they have is not the original version, so
that the original author's reputation will not be affected by problems that might be introduced by others.
Finally, software patents pose a constant threat to the existence of any free program. We wish to make sure that a
company cannot effectively restrict the users of a free program by obtaining a restrictive license from a patent holder.
Therefore, we insist that any patent license obtained for a version of the library must be consistent with the full freedom
of use specified in this license.
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 order to permit linking those libraries into non-free programs.
When a program is linked with a library, whether statically or using a shared library, the combination of the two is legally
speaking a combined work, a derivative of the original library. The ordinary General Public License 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 standard. To achieve this, non-free programs must be allowed to use the library. A more
frequent case is that a free library does the same job as widely used non-free libraries. In this case, there is little to gain
by limiting the free library to free software only, so we use the Lesser General 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.
GNU LESSER GENERAL PUBLIC LICENSE
TERMS AND CONDITIONS FOR COPYING, DISTRIBUTION AND MODIFICATION
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 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 "modification".)
"Source code" for a work means the preferred form of the work for making modifications to it. For a library, complete
source code means all the source code for all modules it contains, plus any associated interface definition files, plus the
scripts used to control compilation and installation of the library.
Activities other than copying, distribution and modification are not covered by this License; they are outside its scope. The