The Lisp Lesser General Public License is the GNU Lesser General Public License version 2.1 (LGPL) with a preamble from Franz (makers of Allegro Common Lisp).

Use of LLGPL is discouraged for the following reasons:

  1. The Franz preamble does not make sense when applied to LGPL version 3 (the section numbers are different).
  2. In 2004, the Free Software foundation affirmed that "the LGPL works as intended with all known programming languages" and that "LGPL contains no special provisions for inheritance, because none are needed." There is no need for the linking and inheritance provisions that are in the Franz preamble.
  3. In 2013, Eli Greenbaum published a detailed examination of the LLGPL in the International Free and Open Source Software Law Review (Volume 5, Issue 1), concluding that "the clarifications made by the LLGPL to the original GNU license are largely unnecessary, and that the LGPL would probably be interpreted in a similar fashion without the clarifications proposed by the LLGPL."
[Comment: There is very much a need for Franz's linking provisions. Using an LLGPL library constrains an application programmer strictly less than the LGPL does during application delivery to an end user. Under the LLGPL, the application programmer need not provide for the end user to be able to relink the application's executable with the end user's own changes to the library. -vm]

The Free Software Foundation recommends publishing your software under the GNU General Public License version 3 or later. See the FSF explanation of why you should use the GPL instead of the LGPL.

For more information about LGPL and the GPL, see the GNU Licenses FAQ

Pages in the LLGPL topic: