From kde-licensing  Mon Apr 07 09:32:53 2003
From: Matthias Ettrich <ettrich () trolltech ! com>
Date: Mon, 07 Apr 2003 09:32:53 +0000
To: kde-licensing
Subject: QPL still needed?
X-MARC-Message: https://marc.info/?l=kde-licensing&m=104970829609721


At present, the Qt Free Edition is dual licensed under both the GNU GPL and 
the QPL.

I'm wondering what the benefit is, except confusing the dual licensing scheme 
and historical reasons.

As I see it the biggest benefit of the QPL is that you can use the Qt Free 
Edition to run commerical Qt software dynamically linked, e.g. the Opera 
browser, and distribute the two together. This makes sense, nobody wants to 
have two identical libraries in memory just because of different license 
terms.

Currently this isn't permitted by the GPL, but by the QPL:

   "5. You may use the original or modified versions of the Software to
   compile, link and run application programs legally developed by you
   or by others."

However, this could easily be achieved with a little addition to the GNU GPL, 
practically the reverse case of 
http://www.gnu.org/licenses/gpl-faq.html#WritingFSWithNFLibs

Are there other reasons for the QPL? Is there any code out there under OS 
licenses that satisfies the requirements of the QPL but not the GNU GPL? The 
non-GPL code in KDE that I'm aware of grants a superset of rights (typically 
X11 or BSD-style licenses), meaning linking to a GPL'ed library is not a 
problem at all. 

Is anybody aware of a counter example?

Matthias