is there really no good gui builder

Ben Finney bignose+hates-spam at benfinney.id.au
Sun Nov 9 07:45:33 EST 2008


Duncan Booth <duncan.booth at invalid.invalid> writes:

> Mr.SpOOn wrote:
> > What's the problem with qt licence?
> 
> "You must purchase a Qt Commercial License from Qt Software or from
> one of its authorized resellers before you start developing
> commercial software. The Commercial license does not allow the
> incorporation of code developed with the Open Source Edition of Qt
> into a commercial product."

This text is at <URL:http://trolltech.com/products/appdev/licensing>,
for those following along at home.

The above statement is confusing and misleading. There is nothing
about the GPL that prevents commercial software; in fact, selling
software to support development is positively encouraged.

The GPL itself explicitly says this. GPL version 2: “You may charge a
fee for the physical act of transferring a copy, and you may at your
option offer warranty protection in exchange for a fee.” GPL version
3: “You may charge any price or no price for each copy that you
convey, and you may offer support or warranty protection for a fee.”

What that page says could be correct if, instead of falsely claiming
that *commercial* software requires a separate license, it rather said
that if you want to redistribute Qt with *restrictions* on the
recipient additional to those in the GPL, you cannot use the GPL as
the license. They offer a separate license (the confusingly-named
“commercial license”) that permits some additional restrictions on
the recipient of your software.

> In effect this means that if you want to develop any commercial
> software with Qt you have to buy the license in advance (even if all
> you want is to knock together some proof-of-concept) and you are
> also permanently locked out from including any previously developed
> Qt code which the wider community may have produced.

That is a common misconception, which is not made any better by
misleading text like that found at the above page, and misleading
dichotomies like GPL versus “commercial license”. A careful reader
of the GPL will see that there is explicitly *no* restriction placed
on redistributing the work commercially: any fee may be charged.

> With other GPL licensed software you have the option of approaching
> the original author and negotiating with them for their code to be
> relicensed for use within your proprietary product

This option remains with Qt also, of course, Anyone is free to attempt
such negotiations.

> It is a novel interpretation of the GPL. Qt Software have every
> right to impose this sort of condition, but it makes me want to
> avoid them.

No, they have no such right to interpret the GPL this way; it would be
entirely incompatible with the GPL since it would be an imposition of
additional restrictions, resulting in work that could not legally be
redistributed at all.

In fact, I don't think they are making such an interpretation, though
their poorly-worded web page that you quoted certainly encourages
readers to make such a false interpretation.

-- 
 \     “I know you believe you understood what you think I said, but I |
  `\         am not sure you realize that what you heard is not what I |
_o__)                                     meant.” —Robert J. McCloskey |
Ben Finney



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