[FYI] QT4 licensing looks very bad for *BSD

[Josh Ockert]

I'm not so sure you guys have this right.

No BSD-licensed code is allowed to use a GPL library and remain
BSD-licensed. According to the GPL, Section 2:

"b) You must cause any work that you distribute or publish, that in
whole or in part contains or is derived from the Program or any part
thereof, to be licensed as a whole at no charge to all third parties
under the terms of this License."

This very specifically includes works which use libraries; use of
libraries with non-GPL software is to be done with the LGPL. That's
why the first L in LGPL used to stand for "Library". Now it stands for
"Lesser", because RMS wants to discourage its use; he has in fact
claimed that many projects have been made open source because they
wanted to use the readline library: "The Readline library implements
input editing and history for interactive programs, and that's a
facility not generally available elsewhere. Releasing it under the GPL
and limiting its use to free programs gives our community a real
boost. At least one application program is free software today
specifically because that was necessary for using Readline" (see
http://software.newsforge.com/software/04/07/15/163208.shtml).

The GPL clarifies this point: "This General Public License does not
permit incorporating your program into proprietary programs. If your
program is a subroutine library, you may consider it more useful to
permit linking proprietary applications with the library. If this is
what you want to do, use the GNU Library General Public License
instead of this License." While this only explicitly refers to
proprietary licenses, other open source licenses are also excluded
because the 'viral' part of the GPL requires that they be distributed
under the terms of "this License" (meaning the GPL).

I believe where the confusion comes in is here: The QT Public License.
It allowed redistribution of any linked work under any Open Source
license. To wit:

"6. You may develop application programs, reusable components and
other software items that link with the original or modified versions
of the Software. These items, when distributed, are subject to the
following requirements: (a) You must ensure that all recipients of
machine-executable forms of these items are also able to receive and
use the complete machine-readable source code to the items without any
charge beyond the costs of data transfer. (b) You must explicitly
license all recipients of your items to use and re-distribute original
and modified versions of the items in both machine-executable and
source code forms. The recipients must be able to do so without any
charges whatsoever, and they must be able to re-distribute to anyone
they choose. (c) If the items are not available to the general public,
and the initial developer of the Software requests a copy of the
items, then you must supply one."

You can read a whole flamewar on the Debian lists from when the QPL
was first coming out:
http://lists.debian.org/debian-legal/1999/03/msg00064.html

If QT4 is licensed exclusively under GPL I do not believe that BSDL
software can continue to be written with it without exploiting some
kind of legal loophole. I'd need to read the GPL in more detail before
giving my opinion. Please note that I'm not a licensed lawyer, just a
law geek applying to law school and finishing up his senior year in
undergrad; take my opinion with a grain of salt. But please do look up
the references, and if you have doubts, read the BSDL, the QPL, the
GPL, and the LGPL, and any clarifying text thereon.