63
LICENSE AGREEMENTS
End User License Agreement for Operating System Software
GNU LESSER GENERAL PUBLIC LICENSE Version 2.1, February 1999
Copyright © 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 is not allowed.
[This is the 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 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 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 modied 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 specied 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 ts 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 nonfree
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 nonfree 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 modied version of the Library.
The precise terms and conditions for copying, distribution and modication follow.
Pay close attention to the difference between a “work based on the ilbrary” 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 license 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 modications and/or translated
straightforwardly into another language. (Hereinafter, translation is included without
limitation in the term “modication”.)
“Source code” for a work means the preferred form of the work for making
modications to it. For a library, complete source code means all the source code for
all modules it contains, plus any associated interface denition les, plus the scripts
used to control compilation and installation of the library.
Activities other than copying, distribution and modication are not covered by this
License; they are outside its scope. The act of running a program using the Library
is not restricted, and output from such a program is covered only if its contents
constitute a work based on the Library (independent of the use of the Library in a tool
for writing it). Whether that is true depends on what the Library does and what the
program that uses the Library does.
1. You may copy and distribute verbatim copies of the Library’s complete source
code as you receive it, in any medium, provided that you conspicuously and
appropriately publish on each copy an appropriate copyright notice and disclaimer of
warranty; keep intact all the notices that refer to this License and to the absence of
any warranty; and distribute a copy of this License along with the Library.
You may charge a fee for the physical act of transferring a copy, and you may at
your option offer warranty protection in exchange for a fee.
2. You may modify your copy or copies of the Library or any portion of it, thus forming
a work based on the Library, and copy and distribute such modications or work under
the terms of Section 1 above, provided that you also meet all of these conditions:
a) The modied work must itself be a software library.
b) You must cause the les modied to carry prominent notices stating that
you changed the les and the date of any change.
c) You must cause the whole of the work to be licensed at no charge to all
third parties under the terms of this License
d) If a facility in the modied Library refers to a function or a table of data to
be supplied by an application program that uses the facility, other than as
an argument passed when the facility is invoked, then you must make a
good faith effort to ensure that, in the event an application does not supply
such function or table, the facility still operates, and performs whatever
part of its purpose remains meaningful. (For example, a function in a
library to compute square roots has a purpose that is entirely well-dened
independent of the application. Therefore, Subsection 2d requires that
any application-supplied function or table used by this function must be
optional: if the application does not supply it, the square root function
must still compute square roots.)