Subject GPL, MPL, IPL, and JPL
Author Jim Starkey
The following is taken verbatim from the Free Software
Foundations license page:

The Mozilla Public License (MPL).
This is a free software license which is not a strong copyleft; unlike
the X11 license, it has some complex restrictions that make it incompatible
with the GNU GPL.
That is, a module covered by the GPL and a module covered by the MPL
cannot legally be linked together. We urge you not to use the MPL for this

However, MPL 1.1 has a provision (section 13) that allows a program
(or parts of it) to offer a choice of another license as well. If part of a
program allows the
GNU GPL as an alternate choice, or any other GPL-compatible license as
an alternate choice, that part of the program has a GPL-compatible license.

The IPL is Mozilla with "Borland" replacing "Netscape". Likewise
JPL is Mozilla with "Jim" replaceing "Netscape".

GPL, probably even LGPL, and Interbase/Firebird/IBPhoenix do not

Jim Starkey