[GRASS-dev] v.digit: Qt or wxWidgets

[Glynn Clements]

Radim Blazek wrote:

> > > I don't care which toolkit you choose. I just don't like to see
> > > that some people for some strange reasons repeat to say that
> > > Qt is not free, which is not true.
> >
> > The licensing information on the TrollTech site suggests that the
> > licence for the Open Source edition isn't actually the GPL, but a
> > requirement that you publish your code under the terms of the GPL.
> >
> > The GPL itself does not require that you publish your code at all. You
> > are free to create derivative works and not publish them at all. /If/
> > you publish them, you must do so under the terms of the GPL.
> >
> > TrollTech's site suggests that you cannot develop "in-house"
> > applications using the Qt Open Source edition (and you can't obtain a
> > commercial licence for software which was originally developed using
> > the Open Source edition). In which case, the licence isn't even
> > GPL-compatible.
> 
> I cannot find anything like that. The opensource package is licenced under
> GPL and I don't see any exception. Where is written that you
> must publish your code even if you do not distribute the application
> or that you cannot develop and use "in-house" application using open source
> edition of Qt?

http://www.trolltech.com/products/qt/licenses/licensing

	You must purchase a Qt Commercial License from Trolltech or
	from any of its authorized resellers before you start
	developing proprietary software. The Commercial license does
	not allow the incorporation of code developed with the Open
	Source Edition of Qt into a proprietary product.

http://www.trolltech.com/products/qt/licenses/licensing/opensource

	Based on the "Quid Pro Quo" principle, if you wish to derive a
	commercial advantage by not releasing your application under
	an open source license, you must purchase an appropriate
	number of commercial licenses from Trolltech. By purchasing
	commercial licenses, you are no longer obliged to publish your
	source code.

http://www.trolltech.com/developer/downloads/qt/faq

	If you are working in a commercial environment and are
	required to keep the source code of your product closed, you
	must use the commercial version instead. Trolltech's
	commercial license terms do not allow you to start developing
	proprietary software using the Open Source edition.

http://www.trolltech.com/developer/downloads/qt/x11

	If you are writing proprietary/commercial software, or if you
	plan to commercialize the software you are writing with Qt,
	you must use a commercial version of Qt. Please refer to the
	Open Source Downloads info page for reasons why.

Now, all of these could be considered mistakes in wording, based upon
the assumption that the software will ultimately be distributed. Or
they could be the result of TrollTech misunderstanding the
consequences of releasing Qt under the GPL. Or they could be a
calculated attempt to sell more commercial licences by misleading
users as to the scope of the rights granted by the GPL.

If the only licence which is included in the official Qt Open Source
version distributed by TrollTech is a copy of the GPL, then there's no
problem. You have the rights stated there regardless of TrollTech's
interpretation of them.

-- 
Glynn Clements <glynn at gclements.plus.com>