References
89
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.