86
LICENSE AGREEMENTS (continued)
End User License Agreements for Operating System Software (continued)
GNU LESSER GENERAL PUBLIC LICENSE
Version 2.1, February 1999
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 verbatim copies of this license document, but changing it is not allowed.
[This is the fi rst 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.]
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 fi rst 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 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 fi les 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 modifi ed 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 specifi ed 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 fi ts its criteria of freedom. The Lesser General Public License
permits more lax criteria for linking other code with the library.
