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 LesserGeneral 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
attempt otherwise to copy, modify, sublicense, link with, or License.
Any 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 iscopyrighted by
the Free Software Foundation, write to the FreeSoftware 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!
.
