QPL vs GPL for QT and derivatives

[Miguel Mendez]

On Tue, 3 May 2005 03:16:17 +0200
Danny Pansters <danny at ricin.com> wrote:

> QT and derivs have either the GPL (2) or QPL license but we have and use the 
> GPL one.
 
> First question: do they differ in distribution, eg x11-gpl versus the qpl 
> version? I never tried but I'm sure someone did/knows/asked.

No, it's what the developer chooses. If you're going to develop a
closed source app like Opera you have you purchase a license. If you
intend to write a GPL'd app then you abide by the GPL, and if you
want to write a BSDL'd program you abide by the QPL. The source
code is the same.

> Second question: if they are the same source wise, the QPL seems a lot more 
> BSD-like: it basically says: can use if not commercial without disclosing 
> source, should one want to. In essence any BSD app under QT should live 
> happily under that, the burden is on the person who would want to use that 
> code next _and_ it could be GPL'ed at any time if she wants to, with the 
> original being left QPL'ed which for us basically means BSD'ed as long as not 
> commercial (and it's not like the fees will starve you if you want them).

Yes, you cannot take a BSDL'd QT app and close the source without
buying a QT license. WRT licensing, if your code is going to be BSD you
have no choice but use the QPL version, since the GPL one would force
you to release your code under the GPL as well. Another interesting
point, and something some GPL advocates fail to understand a lot of
times, is that you cannot relicense code you didn't write. If a GPL
zealot takes a BSD app and tries to 'save it' by releasing a derivative
under the GPL, only his modifications will be under said license, the
original (C) and license still remain.

> Third: if they are not the same source wise, does anyone have any idea if it's 
> a huge leap and perhaps (implied) a regression, in that case it's likely out 
> of the question for practical reasons alone.

The source code is the same.
 
> Thus I'm wondering, are there technical problems or philosophical ones with 
> using the QPL rather than GPL with qt? Perhaps it just never came up, or 
> people don't find it important. I personally think the QPL is rather fair and 
> generous. From a BSDL standpoint it may be preferred over GPL2 (If GPL3 gets 
> as bad as some fear it will never be widespread adapted, we shouldn't worry 
> about GPL3 IMHO, and neither will it be so bad). What are your opinions/added 
> knowledge or facts or thoughts on this?

I don't see any technical problems, i.e. the QPL version is not
crippled in any way. On the philosophical side of things, it's up to
you. If you want to release your code under the BSD license you have to
abide by the QPL. The GPL2 vs GPL3 is a can of worms I'm not going to
open :)

> Some may find it nitpicking, and perhaps it is, but I'd still like to hear 
> some opinions on this anyhow. I could get the bare info by (quite a long) 
> google probably but I'm also interested in hearing opinions. This is an 
> opinionated subject anyway, I know. 

Considering that you've asked in a FreeBSD mailing list I'd expect the
BSD license to be favored here. FWIW, there are several QT apps in the
ports tree released under the BSD license. Off the top of my head,
sysutils/barry, x11-themes/qinx and sysutils/thefish's QT frontend.
Surely there are more out there. ISTR some parts of KDE are under the
BSDL as well.

Cheers,
-- 
Miguel Mendez <flynn at energyhq.es.eu.org>
http://www.energyhq.es.eu.org
PGP Key: 0xDC8514F1

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