13
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 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 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 2d requires that any
application-supplied function or table used by this function
00_MC2_OM-2.book Page 13 Monday, May 25, 2009 9:39 AM
