GNU LESSER GENERAL PUBLIC LICENSE
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 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 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 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 (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
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.
3. 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 2, instead of to this License. (If a
newer version than version 2 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 2) in object code or executable
form under the terms of Sections 1 and 2 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 2 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.
5. A program that contains no derivative of any portion of the
Library, but is designed to work with the Library by being
compiled or linked with it, is called a "work that uses the
Library". Such a work, in isolation, is not a derivative work of
the Library, and therefore falls outside the scope of this
License.
However, linking a "work that uses the Library" with the
Library creates an executable that is a derivative of the Library
(because it contains portions of the Library), rather than a
"work that uses the library". The executable is therefore
covered by this License. Section 6 states terms for distribution
of such executables.
When a "work that uses the Library" uses material from a header
file that is part of the Library, the object code for the work
may be a derivative work of the Library even though the source
code is not. Whether this is true is especially significant if
the work can be linked without the Library, or if the work is
itself a library. The threshold for this to be true is not
precisely defined by law.
If such an object file uses only numerical parameters, data
structure layouts and accessors, and small macros and small
inline functions (ten lines or less in length), then the use of
the object file is unrestricted, regardless of whether it is
legally a derivative work. (Executables containing this object
code plus portions of the Library will still fall under Section
6.)
Otherwise, if the work is a derivative of the Library, you may
distribute the object code for the work under the terms of
Section 6. Any executables containing that work also fall under
Section 6, whether or not they are linked directly with the
Library itself.
6. As an exception to the Sections above, you may also combine
or link a "work that uses the Library" with the Library to
produce a work containing portions of the Library, and distribute
that work under terms of your choice, provided that the terms
permit modification of the work for the customer’s own use and
reverse engineering for debugging such modifications.
You must give prominent notice with each copy of the work that
the Library is used in it and that the Library and its use are
covered by this License. You must supply a copy of this License.
If the work during execution displays copyright notices, you must
include the copyright notice for the Library among them, as well
as a reference directing the user to the copy of this License.
Also, you must do one of these things:
a) Accompany the work with the complete corresponding
machine‐readable source code for the Library including
whatever
changes were used in the work (which must be distributed
under
Sections 1 and 2 above); and, if the work is an executable
linked
with the Library, with the complete machine‐readable "work
that
uses the Library", as object code and/or source code, so that
the
user can modify the Library and then relink to produce a
modified
executable containing the modified Library. (It is
understood
that the user who changes the contents of definitions files
in the
Library will not necessarily be able to recompile the
application
to use the modified definitions.)
b) Use a suitable shared library mechanism for linking with
the
Library. A suitable mechanism is one that (1) uses at run
time a
copy of the library already present on the user’s computer
system,
rather than copying library functions into the executable,
and (2)
will operate properly with a modified version of the library,
if
the user installs one, as long as the modified version is
interface‐compatible with the version that the work was made
with.
c) Accompany the work with a written offer, valid for at
least three years, to give the same user the materials
specified in Subsection 6a, above, for a charge no more
than the cost of performing this distribution.
d) If distribution of the work is made by offering access to
copy
from a designated place, offer equivalent access to copy the
above
specified materials from the same place.
e) Verify that the user has already received a copy of these
materials or that you have already sent this user a copy.
For an executable, the required form of the "work that uses the
Library" must include any data and utility programs needed for
reproducing the executable from it. However, as a special
exception, the materials to be distributed need not include
anything that is normally distributed (in either source or binary
form) with the major components (compiler, kernel, and so on) of
the operating system on which the executable runs, unless that
component itself accompanies the executable.
It may happen that this requirement contradicts the license
restrictions of other proprietary libraries that do not normally
accompany the operating system. Such a contradiction means you
cannot use both them and the Library together in an executable
that you distribute.
7. You may place library facilities that are a work based on
the Library side‐by‐side in a single library together with other
library facilities not covered by this License, and distribute
such a combined library, provided that the separate distribution
of the work based on the Library and of the other library
facilities is otherwise permitted, and provided that you do these
two things:
a) Accompany the combined library with a copy of the same
work
based on the Library, uncombined with any other library
facilities. This must be distributed under the terms of the
Sections above.
b) Give prominent notice with the combined library of the
fact
that part of it is a work based on the Library, and
explaining
where to find the accompanying uncombined form of the same
work.
8. You may not copy, modify, sublicense, link with, or
distribute the Library except as expressly provided under this
License. Any attempt otherwise to copy, modify, sublicense, link
with, or distribute the Library is void, and will automatically
terminate your rights under this License. However, parties who
have received copies, or rights, from you under this License will
not have their licenses terminated so long as such parties remain
in full compliance.
9. You are not required to accept this License, since you have
not signed it. However, nothing else grants you permission to
modify or distribute the Library or its derivative works. These
actions are prohibited by law if you do not accept this License.
Therefore, by modifying or distributing the Library (or any work
based on the Library), you indicate your acceptance of this
License to do so, and all its terms and conditions for copying,
distributing or modifying the Library or works based on it.
10. Each time you redistribute the Library (or any work based
on the Library), the recipient automatically receives a license
from the original licensor to copy, distribute, link with or
modify the Library subject to these terms and conditions. You
may not impose any further restrictions on the recipients’
exercise of the rights granted herein. You are not responsible
for enforcing compliance by third parties with this License.
11. If, as a consequence of a court judgment or allegation of
patent infringement or for any other reason (not limited to
patent issues), conditions are imposed on you (whether by court
order, agreement or otherwise) that contradict the conditions of
this License, they do not excuse you from the conditions of this
License. If you cannot distribute so as to satisfy
simultaneously your obligations under this License and any other
pertinent obligations, then as a consequence you may not
distribute the Library at all. For example, if a patent license
would not permit royalty‐free redistribution of the Library by
all those who receive copies directly or indirectly through you,
then the only way you could satisfy both it and this License
would be to refrain entirely from distribution of the Library.
If any portion of this section is held invalid or unenforceable
under any particular circumstance, the balance of the section is
intended to apply, and the section as a whole is intended to
apply in other circumstances.
It is not the purpose of this section to induce you to infringe
any patents or other property right claims or to contest validity
of any such claims; this section has the sole purpose of
protecting the integrity of the free software distribution system
which is implemented by public license practices. Many people
have made generous contributions to the wide range of software
distributed through that system in reliance on consistent
application of that system; it is up to the author/donor to
decide if he or she is willing to distribute software through any
other system and a licensee cannot impose that choice.
This section is intended to make thoroughly clear what is
believed to be a consequence of the rest of this License.
12. If the distribution and/or use of the Library is restricted
in certain countries either by patents or by copyrighted
interfaces, the original copyright holder who places the Library
under this License may add an explicit geographical distribution
limitation excluding those countries, so that distribution is
permitted only in or among countries not thus excluded. In such
case, this License incorporates the limitation as if written in
the body of this License.
13. The Free Software Foundation may publish revised and/or new
versions of the Lesser General Public License from time to time.
Such new versions will be similar in spirit to the present
version, but may differ in detail to address new problems or
concerns.
Each version is given a distinguishing version number. If the
Library specifies a version number of this License which applies
to it and "any later version", you have the option of following
the terms and conditions either of that version or of any later
version published by the Free Software Foundation. If the
Library does not specify a license version number, you may choose
any version ever published by the Free Software Foundation.
14. If you wish to incorporate parts of the Library into other
free programs whose distribution conditions are incompatible with
these, write to the author to ask for permission. For software
which is copyrighted by the Free Software Foundation, write to
the Free Software Foundation; we sometimes make exceptions for
this. Our decision will be guided by the two goals of preserving
the free status of all derivatives of our free software and of
promoting the sharing and reuse of software generally.
NO WARRANTY
15. BECAUSE THE LIBRARY IS LICENSED FREE OF CHARGE, THERE IS NO
WARRANTY FOR THE LIBRARY, TO THE EXTENT PERMITTED BY APPLICABLE
LAW. EXCEPT WHEN OTHERWISE STATED IN WRITING THE COPYRIGHT
HOLDERS AND/OR OTHER PARTIES PROVIDE THE LIBRARY "AS IS" WITHOUT
WARRANTY OF ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING, BUT
NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
FITNESS FOR A PARTICULAR PURPOSE. THE ENTIRE RISK AS TO THE
QUALITY AND PERFORMANCE OF THE LIBRARY IS WITH YOU. SHOULD THE
LIBRARY PROVE DEFECTIVE, YOU ASSUME THE COST OF ALL NECESSARY
SERVICING, REPAIR OR CORRECTION.
16. IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO
IN WRITING WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MAY
MODIFY AND/OR REDISTRIBUTE THE LIBRARY AS PERMITTED ABOVE, BE
LIABLE TO YOU FOR DAMAGES, INCLUDING ANY GENERAL, SPECIAL,
INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING OUT OF THE USE OR
INABILITY TO USE THE LIBRARY (INCLUDING BUT NOT LIMITED TO LOSS
OF DATA OR DATA BEING RENDERED INACCURATE OR LOSSES SUSTAINED BY
YOU OR THIRD PARTIES OR A FAILURE OF THE LIBRARY TO OPERATE WITH
ANY OTHER SOFTWARE), EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN
ADVISED OF THE POSSIBILITY OF SUCH DAMAGES.
END OF TERMS AND CONDITIONS
How to Apply These Terms to Your New Libraries
If you develop a new library, and you want it to be of the
greatest possible use to the public, we recommend making it free
software that everyone can redistribute and change. You can do
so by permitting redistribution under these terms (or,
alternatively, under the terms of the ordinary General Public
License).
To apply these terms, attach the following notices to the
library. It is safest to attach them to the start of each source
file to most effectively convey the exclusion of warranty; and
each file should have at least the "copyright" line and a pointer
to where the full notice is found.
<one line to give the library’s name and a brief idea of what
it does.>
Copyright (C) <year> <name of author>
This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later
version.
This library is distributed in the hope that it will be
useful,
but WITHOUT ANY WARRANTY; without even the implied warranty
of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General
Public
License along with this library; if not, write to the Free
Software
Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
02110‐1301 USA
Also add information on how to contact you by electronic and
paper mail.
You should also get your employer (if you work as a programmer)
or your school, if any, to sign a "copyright disclaimer" for the
library, if necessary. Here is a sample; alter the names:
Yoyodyne, Inc., hereby disclaims all copyright interest in the
library ‘Frob’ (a library for tweaking knobs) written by James
Random Hacker.
<signature of Ty Coon>, 1 April 1990
Ty Coon, President of Vice
That’s all there is to it!
|
HTML rendering created 2022-12-18 by Michael Kerrisk, author of The Linux Programming Interface, maintainer of the Linux man-pages project. For details of in-depth Linux/UNIX system programming training courses that I teach, look here. Hosting by jambit GmbH. |
|