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
114
