Which GUI toolkit is THE best?

Paul Boddie paul at boddie.org.uk
Mon Mar 13 19:55:45 CET 2006

Paul Rubin wrote:
> "Paul Boddie" <paul at boddie.org.uk> writes:
> > 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.
> What is the deal here?  Why would they refuse, to someone willing to
> pay the commercial license fee?  They are a business, and as such,

Well, I can't answer for them in any sense (and I should ask you to
substitute any company with a similar business model for Trolltech in
the text, along with accompanying product names, in order to emphasize
the mere speculative nature of my explanation), but all I was trying to
do was to explain the pattern of behaviour that goes something like

 1. Developer downloads Qt GPL edition.
 2. Developer develops product based on Qt.
 3. Some time later, with finished product, developer now wants
    to release a closed source version of the product.
 4. Developer approaches Trolltech and asks for a commercial
    licence in order to ship a closed source product.

Now, since the commercial licence is "per developer", some cunning
outfit could claim that only one developer wrote their product (rather
than one hundred developers, say), but this would be a fairly big
breach of trust (although nothing unusual in the world of commerce, I'm
sure). Would a business making software for other such businesses care
about such things? What kind of recourse would they have?

> they presumably like gettng money.  And someone wanting to develop a
> proprietary app with Qt that users have to pay for, shouldn't mind
> paying Trolltech for the commercial Qt license.

It's the "after the fact" switching from GPL to commercial licensing,
rather than the up-front "wanting to develop" scenario, that would be
difficult for anyone issuing commercial licences to monitor. Trolltech
specifically mention "exposure to the GPL" on their "open source
downloads" page presumably (and again I speculate, so beware!) to
suggest that if you want to end commercial, you need to start


I don't see why anyone planning to make big bucks on proprietary
software can't shell out for the technology which would make their
success possible, either. But anyway, the key part of my explanation
was that the copyright holder can always refuse to license their work
to you. Obviously, if they've already licensed it to you under the GPL,
you'll always have that kind of permission.


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