14
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
00_MC2_OM-2.book Page 14 Monday, May 25, 2009 9:39 AM
