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:
The modified work must itself be a software
library.
You must cause the files modified to carry
prominent notices stating that you changed the
files and the date of any change.
You must cause the whole of the work to be
licensed at no charge to all third parties under the
terms of this License.
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.
a)
b)
c)
d)
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