Is Qt holding KDE back?

[medin]

@Herzenschein

The licensing isn’t holding KDE back either.

Because KDE Project had special agreement with them called KDE Free Qt Foundation Agreement, which is not applied for others.

[Duha]

Isn’t GTK also LGPL licensed? So the “issue” with the appstore also affects them.

[medin]

@redstrate

This is simply not true, there is the possibility of developing commercial software in Qt without paying a dime. Most of the modules are possible to use via LGPL, and you must ship Qt externally to abide by the license. See this page on Qt’s website: Qt - Obligations of the GPL and LGPL.

Anything that plays in the swamp via that ambiguous dual licensing is dangerous for developers who want to create their own apps.

Until Qt doesn’t make their platform fully free and open source, no one is ready to invest time and effort to learn Qt.

[medin]

GTK has no restrictions for commercial usage.

[g-fb]

What’s so hard to understand? They have the same license. You can do with LGPL Qt libraries the same things you can do with LGPL GTK libraries.

[medin]

@g-fb

What’s so hard to understand? They have the same license. You can do with LGPL Qt libraries the same things you can do with LGPL GTK libraries.

[Duha]

I think you misunderstand. Dual licensing cant take rights away.

[g-fb]

Yes, it’s been stated before not all Qt libraries are LGPL. But many are and those can be used the same way as GTK libraries.

[Franken14679]

@redstrate

Programming is not what casual users do

I would go further –

• AFAICS, about 1 % of the human beings on this planet can effectively program computers.
  Putting it another way – “Programming computers is the most difficult task mankind has placed on itself.” – I’m not the originator of that statement and, I can’t currently find out who originally stated it …

• In my personal view, less than 10 % of the programming community can effectively test implemented code.
  I’m a supporter of peer testing and dedicated testing teams – module test; integration test; system test.
  I’m also a supporter of the “V model” – Requirements → Design and Architecture → Implementation → Test → Acceptance « Yet another testing team but, this time the customer’s personnel … »

---

And, I’ve just now stumbled over a wonderful quote:

On two occasions, I have been asked [by members of Parliament], ‘Pray, Mr. Babbage, if you put into the machine wrong figures, will the right answers come out?’ I am not able to rightly apprehend the kind of confusion of ideas that could provoke such a question.

• Charles Babbage (1791 – 1871)

[jinliu]

@redstrate

This is a pretty baseless accusation to make, we almost certainly do care. Some developers are trying to bring down the amount of runtime errors in Plasma 6

No, that was not meant to be an accusation. Rather, I do think that is the right way to use QML - just ignore these warnings, as long as it doesn’t break.

[medin]

it’s been stated before not all Qt libraries are LGPL

I’m afraid only KDE Project has enough power to protect itself from any future changes in that evil dual licensing model under future owners of Digia company, others have no power to defend their works.

[jackh]

I doubt Qt would want to stop providing a FOSS license. I’m sure they appreciate the exposure that FOSS projects like KDE, qBittorrent, etc give them. Also I watched a presentation once where they showed ~30% of commits were done by external contributors.

[Herzenschein]

@medin

I don’t think so, that dual licensing is too much restricted and tricky, it actually prohibits a developer from selling his/her app via known stores.

I think the mixup here is that the open source offer does not come with a dual license where you have to abide to both at the same time. When you use the open source offer, what matters is each module’s license, which most of the time will be LGPL, the same as GTK, 7zip, ffmpeg, libvlc, etc.

You can choose to use the commercial license by paying for it because it provides certain benefits to companies. As an open source developer, you don’t touch the commercial license unless you want to pay for it.

In that screenshot mentioning application stores, the mentioned issues derive from the license being GPL or LGPL, not from Qt’s license. That is precisely because the GPL/LGPL are copyleft and have requirements to ensure the freedom of the application user. A GTK app will have the same requirements and have the same issues on such a sucky hypothetical store.

In that screenshot where it says “Add-ons available under Commercial Licenses, or GNU General Public License”, it means that you can use them as GPL modules, but if you pay for it, you can choose to use the commercial license instead because it can get you less headaches than fulfilling the requirements of the free and copyleft GPL.

[redstrate]

It should be noted that while these are under GPL or Commerical, KDE and FOSS provide alternative solutions to these. For example, Qt Charts can be replaced by KQuickCharts (LGPL), Qt Virtual Keyboard could be replaced by Maliit (LGPL), and Qt Wayland Compositor could be wlroots (MIT)

Of course, if you are a business you would probably go with none of these and shell out a commerical license for peace of mind (Of course, that’s the whole point of the dual license)

@jinliu

No, that was not meant to be an accusation. Rather, I do think that is the right way to use QML - just ignore these warnings, as long as it doesn’t break.

Thanks for clearing it up, and there’s even some warnings that will eventually be gone in Qt6 as QtQuick gets more lenient.

@medin

Anything that plays in the swamp via that ambiguous dual licensing is dangerous for developers who want to create their own apps.

Have you tried creating your own app using Qt and encountered problems with the dual licensing model? I find it pretty clear where the two licenses fill their roles

[medin]

@redstrate

Have you tried creating your own app using Qt and encountered problems with the dual licensing model? I find it pretty clear where the two licenses fill their roles

I don’t have the courage to use it, even Java and .NET Core haven’t that shady license, if one day KDE project and that Foundation holding the agreement both ceased to exist, and the new owner of Digia changed again the license model then we will see who can save those developers who used that free license for creating their apps.

Many apps changed their license/pricing model in the last years to increase their incomes, so it’s not surprising if the same move will be attempted by some framework creators like how Unity started that small storm to keep itself alive.

[redstrate]

I suggest reading the KDE Free Qt Foundation - KDE Community page, which details why this is unlikely to happen and the sorts of protections the agreement gives

[ulterno]

Here’s a perspective:
I started programming with C Language and even when I used C++, I mostly didn’t use the std::… classes.
By the time I was thinking of learning those, I stumbled upon Qt Framework (thanks to KDE).

Having used Qt for a few months (learning mainly by the documentation that’s very conveniently available with “F1” in Qt Creator), I started learning the usage of equivalents in the std namespace.

And from what I see, the Qt Classes and functions have way more versatile classes, with most having functions not only for STL compatibility, but also having Java style syntaxes.
On top of these, Qt has a GUI creation system that was far easier to pickup than MS Visual Studio AND has easy cross-compilation options.

Also, from what I have seen, people tend to use there STL functions in KDE projects when they feel like it. Not really much of a problem other than the times you need to connect to Qt Widgets, in which case most data types are easily convertible.

After learning enough of both to understand their usage, I tend to use more of Qt Classes.