http://opensource.franz.com/preamble.html

Preamble to the Gnu Lesser General Public License

Copyright (c) 2000 Franz Incorporated, Berkeley, CA 94704

The concept of the GNU Lesser General Public License version 2.1
("LGPL") has been adopted to govern the use and distribution of
above-mentioned application. However, the LGPL uses terminology that
is more appropriate for a program written in C than one written in
Lisp. Nevertheless, the LGPL can still be applied to a Lisp program if
certain clarifications are made. This document details those
clarifications. Accordingly, the license for the open-source Lisp
applications consists of this document plus the LGPL. Wherever there
is a conflict between this document and the LGPL, this document takes
precedence over the LGPL.

A "Library" in Lisp is a collection of Lisp functions, data and
foreign modules. The form of the Library can be Lisp source code (for
processing by an interpreter) or object code (usually the result of
compilation of source code or built with some other
mechanisms). Foreign modules are object code in a form that can be
linked into a Lisp executable. When we speak of functions we do so in
the most general way to include, in addition, methods and unnamed
functions. Lisp "data" is also a general term that includes the data
structures resulting from defining Lisp classes. A Lisp application
may include the same set of Lisp objects as does a Library, but this
does not mean that the application is necessarily a "work based on the
Library" it contains.

The Library consists of everything in the distribution file set before
any modifications are made to the files. If any of the functions or
classes in the Library are redefined in other files, then those
redefinitions ARE considered a work based on the Library. If
additional methods are added to generic functions in the Library,
those additional methods are NOT considered a work based on the
Library. If Library classes are subclassed, these subclasses are NOT
considered a work based on the Library. If the Library is modified to
explicitly call other functions that are neither part of Lisp itself
nor an available add-on module to Lisp, then the functions called by
the modified Library ARE considered a work based on the Library. The
goal is to ensure that the Library will compile and run without
getting undefined function errors.

It is permitted to add proprietary source code to the Library, but it
must be done in a way such that the Library will still run without
that proprietary code present. Section 5 of the LGPL distinguishes
between the case of a library being dynamically linked at runtime and
one being statically linked at build time. Section 5 of the LGPL
states that the former results in an executable that is a "work that
uses the Library." Section 5 of the LGPL states that the latter
results in one that is a "derivative of the Library", which is
therefore covered by the LGPL. Since Lisp only offers one choice,
which is to link the Library into an executable at build time, we
declare that, for the purpose applying the LGPL to the Library, an
executable that results from linking a "work that uses the Library"
with the Library is considered a "work that uses the Library" and is
therefore NOT covered by the LGPL.

Because of this declaration, section 6 of LGPL is not applicable to
the Library. However, in connection with each distribution of this
executable, you must also deliver, in accordance with the terms and
conditions of the LGPL, the source code of Library (or your derivative
thereof) that is incorporated into this executable.

End of Document