GNU LESSER GENERAL PUBLIC LICENCE
This is an unofficial translation of the GNU General Public Licence into [language]. It was not published by the Free Software Foundation and does not legally state the distribution terms for software that uses the GNU GPL— only the original English text of the GNU GPL does that. However, we hope that this translation will help [language] speakers understand the GNU GPL better.
Version 2.1, February 1999
Copyright (C) 1991, 1999 Free Software Foundation, Inc.
51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
USA
Everyone is permitted to copy and distribute verbatim copies of this licence 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 Licence, version 2, hence the version number 2.1.]
Preamble
The licences for most software are designed to take away your freedom to share and change it. By contrast, the GNU General Public Licences are intended to guarantee your freedom to share and change free software—to make sure the software is free for all its users.
This licence, the Lesser General Public Licence, 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 licence or the ordinary General Public Licence 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 Licences 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 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 licence, 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 licence from a patent holder. Therefore, we insist that any patent licence obtained for a version of the library must be consistent with the full freedom of use specified in this licence.
Most GNU software, including some libraries, is covered by the ordinary GNU General Public Licence. This licence, the GNU Lesser General Public Licence, applies to certain designated libraries and is quite different from the ordinary General Public Licence. We use this licence 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 Licence therefore permits such linking only if the entire combination fits its criteria of freedom. The Lesser General Public Licence permits more lax criteria for linking other code with the library.
We call this licence the "Lesser" General Public Licence because it does Less to protect the user's freedom than the ordinary General Public Licence. 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 Licence for many libraries. However, the Lesser licence 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 Licence.
