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

[Ron Yorston]

Glynn Clements <glynn at gclements.plus.com> wrote:
>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.

I think TrollTech have a very clear understanding of the GPL and its
consequences.

The items quoted from their website all say in different ways that
'you must' use a commercially licensed version of Qt if you want to
distribute your software and keep the source code closed.  This is
not something you could do under the GPL.

The leverage TrollTech have which allows them to say 'you must'
behave in a particular way is that they can refuse to sell you a
commercial licence.  If you want to buy your way out of the GPL's
obligation to publish source you have to do so on TrollTech's terms.

This has no affect on your rights under the GPL.

Ron