14
15
Software License Agreement
<LGPL>
GNU LESSER GENERAL PUBLIC LICENSE
Version 2.1, February 1999
Copyright (C) 1991, 1999 Free Software Foundation, Inc. 59 Temple Place, Suite 0,
Boston, MA 0111-107 USA
Everyone is permitted to copy and distribute verbatim 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 , hence the version number .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 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 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 () 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 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.
. 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 modifications or work under the
terms of Section 1 above, provided that you also meet all of these conditions:
a) The modified work must itself be a software library.
b) You must cause the files modified to carry prominent notices stating that you changed the
files 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 modified 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-defined independent of the application. Therefore, Subsection d 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.)
These requirements apply to the modified work as a whole. If identifiable sections of that
work are not derived from the Library, and can be reasonably considered independent
and separate works in themselves, then this License, and its terms, do not apply to those
sections when you distribute them as separate works. But when you distribute the same
sections as part of a whole which is a work based on the Library, the distribution of the
whole must be on the terms of this License, whose permissions for other licensees extend
to the entire whole, and thus to each and every part regardless of who wrote it.
Thus, it is not the intent of this section to claim rights or contest your rights to work written
entirely by you; rather, the intent is to exercise the right to control the distribution of
derivative or collective works based on the Library.
In addition, mere aggregation of another work not based on the Library with the Library (or
with a work based on the Library) on a volume of a storage or distribution medium does not
bring the other work under the scope of this License.
. You may opt to apply the terms of the ordinary GNU General Public License instead of
this License to a given copy of the Library. To do this, you must alter all the notices that
refer to this License, so that they refer to the ordinary GNU General Public License,
version , instead of to this License. (If a newer version than version of the ordinary
GNU General Public License has appeared, then you can specify that version instead if
you wish.) Do not make any other change in these notices.
Once this change is made in a given copy, it is irreversible for that copy, so the ordinary
GNU General Public License applies to all subsequent copies and derivative works made
from that copy.
This option is useful when you wish to copy part of the code of the Library into a program
that is not a library.
4. You may copy and distribute the Library (or a portion or derivative of it, under Section )
in object code or executable form under the terms of Sections 1 and above provided
that you accompany it with the complete corresponding machine-readable source code,
which must be distributed under the terms of Sections 1 and above on a medium
customarily used for software interchange.
If distribution of object code is made by offering access to copy from a designated place,
then offering equivalent access to copy the source code from the same place satisfies the
requirement to distribute the source code, even though third parties are not compelled to
copy the source along with the object code.
Software License Agreement
(continued)
