Which GUI toolkit is THE best?

Paul Boddie paul at boddie.org.uk
Mon Mar 13 19:15:37 CET 2006

Thomas Guettler wrote:
> Have you read all the text?
> """
> Two qualities of the Qt Commercial License should be emphasized:
> You need it before you start development of proprietary software.
> You must purchase a Qt Commercial License from Trolltech or from any of
> its authorized resellers before you start developing. The Commercial
> license does not allow the incorporation of code developed with the Open
> Source Edition of Qt into a proprietary product.
> """
> There is a GPL version for Linux. But the GPL does not allow linking
> with closed source software.

My understanding of how it all works is this: Trolltech offers you Qt
under the GPL; you can choose to accept the GPL; you then uphold the
GPL in the distribution of your work. Alternatively, you request that
Trolltech license the software to you under the "Qt Commercial
License"; they decide whether or not they want to license it to you; if
they decide "yes", you get to distribute your proprietary software with
the proprietary edition of the product.

What people don't usually understand (or rather complain about loudly)
is that Trolltech can refuse to license Qt to you under the commercial
licence, as is their right as the owner of the copyrighted work. As far
as I know, you can still obtain Qt under the GPL from them in such a
situation, although this is fairly academic since there are lots of
people offering Qt under the GPL in a variety of GNU/Linux
distributions, for example. Usually, the people making a fuss about all
this have already licensed Qt under the GPL, however, and believe that
they have a right to "switch over" to another licence, but neither the
GPL nor any basic aspect of copyright practice supports such a notion.

So, yes, you either say up front that you're developing proprietary
software and buy into that special deal with the copyright holder, or
you don't. Of course, you could try and distribute non-commercial,
evaluation, trial, educational-use-only, non-redistributable or
NDA-affected versions of your favourite proprietary software products
and see which court of law that takes you to - in these debates nobody
seems to ask themselves whether Bill Gates and/or Steve Jobs would let
you switch around, slip out of that NDA, give you special upgrades,
strike through clauses in that EULA, and so on down the list of things
that nobody thought about when putting together that now-shaky business


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