Gtk+ versus Qt [LWN.net]

Gtk+ versus Qt

Posted Mar 22, 2007 2:57 UTC (Thu) by myopiate (guest, #41091)
Parent article: The road to freedom in the embedded world

In a sad kind of irony Nokia seems to have chosen the Gtk+ library over Qt because that would allow them to keep part of their helper library for the embedded small screen proprietary.

I don't see how this is sad or ironic. A proprietary application can be built with Qt, you just have to pay Trolltech a licensing fee. You are basically saying that the Trolltech way (either you make free software or pay me) is a more free way than licencing under LGPL (the Gtk+ way).

The "freeness" of one way over the other is debatable. In my opinion the Gtk+ way is better because the barriers to entry are smaller. I don't have to pay a license fee and I can bootstrap something that pays the bills easily. I can open source the project later if I want. The Trolltech way adds money/time expensive business transactions. Another issue is Non-GPL fee software such as Mozilla can't use Qt without paying licensing fees. Mozilla for Linux uses Gtk+.

What you are peeved about is the propietary-ness of the Nokia platform. I don't think it really has anything to do with the selection of Gtk+ over Qt.

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Gtk+ versus Qt

Posted Mar 22, 2007 8:43 UTC (Thu) by myopiate (guest, #41091) [Link]

I stand corrected :)

But if I want to use Qt, my software still has to be GPL (or FSF compatible) or I need to pay for a commercial license. Does this promote free software, or is it a sales pitch?

In modern computing, a windowing toolkit is amlost as ubiquitous as Libc. Would GNU Libc be where it is today if it were GPL or pay money?

Gtk+ versus Qt

Posted Mar 22, 2007 10:49 UTC (Thu) by BlueLightning (subscriber, #38978) [Link]

FSF or OSI approved licenses. That covers a huge range of licenses. If you want something else, it's likely that you're trying to do something that would allow people to bypass the commercial Qt licensing.

The fact of the matter is, Qt would not be where it is today without the money that Trolltech gets from commercial licensing.

Gtk+ versus Qt

Posted Mar 22, 2007 21:22 UTC (Thu) by oak (subscriber, #2786) [Link]

IMHO Qt is mainly suited for cases where the project is either proprietary or open AND that doesn't change. The case where you have to pay the licencing fees in the ramp up phase while the code goes through legal and management clearances doesn't fly that well, especially if the code is eventually going to be Open Sourced (or that hasn't been decided yet). Gtk gives more freedom in deciding how & when the code depending on it is to be Open Sourced.

Another issue is that Qt doesn't really have a community developing the widget set like is with Gnome/Gtk, it's completely controlled by Trolltech (which is a commercial entity and could get bought out).

C++ ABI compatibility is still a minor issue too. The C++ ABI changed again between GCC 3.x and 4.x.

On the upsides, Qt for example has excellent documentation and something like Doxygen can produce much nicer class hierarchies etc. from C++ code than what gtk-doc can ever produce from Gobject stuff...

Gtk+ versus Qt

Posted Mar 22, 2007 23:55 UTC (Thu) by mmarxmeier (subscriber, #6217) [Link]

> Another issue is that Qt doesn't really have a community developing the
> widget set like is with Gnome/Gtk,

You mean like the KDE devs

> it's completely controlled by
> Trolltech (which is a commercial entity and could get bought out).

http://www.kde.org/whatiskde/kdefreeqtfoundation.php

Gtk+ versus Qt

Posted Mar 23, 2007 21:36 UTC (Fri) by oak (subscriber, #2786) [Link]

>> Another issue is that Qt doesn't really have a community developing
>> the widget set like is with Gnome/Gtk,
>
> You mean like the KDE devs

Don't they develope things atop Qt, instead developing Qt itself?
AFAIK Trolltech doesn't accept changes from others because they
need to have full ownership of everything in Qt to be able
to dual-license its code. Or do they offer also an option
of contributor resigning all the rights to his code to Trolltech?

> http://www.kde.org/whatiskde/kdefreeqtfoundation.php

Yes, the code will be freed if Trolltech is bought, but the
foundation doesn't come with the Qt developers currently in
the Trolltech payroll. Code without a proper knowledge transfer
from the previous maintainers (or without clear owner / decision
process in technical matters) is much harder to maintain. I don't
know whether this would be a problem in practice. It depends a bit
what would happen with Trolltech and its employees and how much
involvement e.g. current KDE devs have with Qt.

Gtk+ versus Qt

Posted Mar 29, 2007 23:19 UTC (Thu) by Duncan (guest, #6647) [Link]

There is, however, rather more to this picture. Trolltech has very
deliberately "poison-pilled" any hostile buyout or takeover attempt.
(Unlike many smaller companies here in the US, it seems they value their
independence and are /not/ simply there to eventually be bought out.) The
currently active licensing arrangement for Qt is GPL/QPL/proprietary. In
practice, what this does is ensure people contribute back to the community
either with code, or if they don't want to do that, at least with money,
so they can take their work built on top proprietary, but in the process
fund the base that's dual licensed GPL as well, thus contributing to
further development of the free software side with money if they refuse to
contribute to it with code. =8^)

This of course has so far done a good job of keeping Trolltech financially
viable, as well as providing a technically great toolkit for use both in
freedomware and in proprietaryware. The "poison-pill" aspect of the
FreeQTFoundation, however, is that should it be triggered, the code would
*NOT* just be "freed" (there's no need for that, it's already free as in
freedom to anyone wishing to make their own code likewise), but would be
BSD-style licensed, thus allowing commercial use without "giving back" in
the form of code or cash, as is now required. Since the code is the same
but for the license, this would immediately devalue the company in terms
of cash-out value, thus discouraging any action that might trigger the
release in the first place.

BTW, it should also be noted that the way the foundation is setup (two
board members each from Trolltech and KDE, with the KDE side ruling in
case of a tie vote), should Trolltech ever cease to act in the interest of
KDE, KDE has the upper hand. Not that they're likely to trigger it in
anything like the foreseeable future, since that would kill the mutually
beneficial relationship that has and continues to benefit KDE greatly, but
it's nice to know that one way or another, KDE has the legal trump card
should it ever be needed.

Duncan