LTS versions of Qt will be available only under a commercial license

(Pedram Pourang) #21

I you really want an alternative to Qt, you’ll need a library that’s tested by many Linux users and is in active development. (1) Qt is the best. (2) GTK is the second choice but the way it’s being developed is annoying (your app will be broken after 6 months or so). (3) EFL is the basis of Enlightenment – the most well-known app based on EFL is Terminology, which is a nice terminal emulator that can play videos :wink: (I prefer QTerminal to it.) (4) wxWidgets is the fourth option. After it, there may be libraries that aren’t used by many.

But, you could also be realistic and stop catastrophizing in your mind: Nothing serious has happened to Qt.

(Alf Gaida) #22

a) Qt will never be closed source - there are ways to prevent this
b) It’s only about LTS, Debian will be not happy about, but as far as i know “Bullseye” will be delivered with the current LTS - so we talk about a approx. 4 year timespan.
c) nothing is written in stone …

(Pedram Pourang) #23

True, realistically.


“wxWidgets is self-torture to me”

I was trying to indicate to dabeegmon that using wxWidgets has its own way of doing things and is different to Qt. There are a lot of classes and functions in the API and so you need to spend time learning how they all work together. The learning curve is large.

“Nothing serious has happened to Qt”.

Yes you are right but I will keep monitoring the situation.

(Luís Pereira) #25


I’m not so certain that that guarantee is ‘valid’.

With the whiff of enough money many things have changed.

If you think this hasn’t effected open source - - - - - take one hard look at Canonical . . . .


(Pedram Pourang) #27

It is possible that Qt will become closed-source. All we say is that it’s improbable. We worry based on probabilities, not possibilities — otherwise, I should constantly worry that a meteorite might fall on my head; which isn’t impossible :wink:

(Luís Pereira) #28


(Alf Gaida) #29

it is nearly impossible that Qt will become closed source - that would mean that the whole Qt has to be rewritten from scratch without using a single line from the previous version - have a look at the license headers:

** Copyright (C) 2016 The Qt Company Ltd.
** Copyright (C) 2015 Klaralvdalens Datakonsult AB, a KDAB Group company,, author David Faure <>
** Contact:
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** accordance with the commercial license agreement provided with the
** Software or, alternatively, in accordance with the terms contained in
** a written agreement between you and The Qt Company. For licensing terms
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** information use the contact form at
** GNU Lesser General Public License Usage
** Alternatively, this file may be used under the terms of the GNU Lesser
** General Public License version 3 as published by the Free Software
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** packaging of this file. Please review the following information to
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** GNU General Public License Usage
** Alternatively, this file may be used under the terms of the GNU
** General Public License version 2.0 or (at your option) the GNU General
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This code will be GPLed forever - really - it can’t be used in the next iteration of Qt as closed source only :smiley:

(Papoteur) #30

The actual material which is already available will always available as open source. What Qt Company can is to close the future improvements to Qt. At this step, “community” has to be organized to host the last open source release and to maintain it.

Qt Company, I presume, has people to pay, servers and so on. It has to found how to collect some money for that. We have also interest that it find a way to have resources.

(Pedram Pourang) #31

I agree.

Very unlikely. Even if we’re talking about our nightmares, this one has a happy ending (community). And it’s rather a nightmare for Qt Company.

Qt Company, I presume, has people to pay, servers and so on

Definitely. And they did that to provide the money. I, for one, have no problem with it. I can also ignore how they patronized open-source users, telling them what’s good for them; words are just words.


Qt changes for 2020 are:

  • Installation of Qt binaries will require a Qt Account
  • Long-term-supported (LTS) releases and the offline installer will become available to commercial licensees only
  • New Qt offering for start-ups and small businesses for $499/year

From February onward, everyone, including open-source Qt users, will require valid Qt accounts to download Qt binary packages.

Regarding your (1) Qt, (2) GTK (3) EFL and (4) wxWidgets ranking, it is my understanding that only 1 & 4 are cross-platform. As I said wxWidgets uses the native available components for the OS which for Linux is gtk (effectively building a gtk app). There are gtk2 and gtk3 wxWidget libraries (I have used gtk2). Some applications built with wxWidgets are listed here. Qt has a consistent API, a logical way of doing things and IMO is great to use and why I use it as my main platform. However, these 2020 changes/restrictions could have all kinds of unexpected ramifications (like open source developers choosing alternative C++ frameworks).

(Pedram Pourang) #33

Since when does a Linux/*BSD user install binaries provided by Qt company?! If he does, he’ll need to learn more about Linux/*BSD or may want to return to Windows/macOS.

Not being a fortune-teller, I rely on a rational estimation of probabilities. We/I explained it above.

(Pedram Pourang) #34

About being cross-platform (not related to Qt’s announcement):

I think LXQt is first and foremost for Linux – and it works with all Linux distros – and only then, for other OS’s if possible. There has been no attempt to make it work on Windows, for example, and I don’t think any LXQt dev cares. Some components (like QTerminal) could be made work on macOS though.


It seems most people are not too concerned about the changes due to the protection offered by the legal agreement with KDE Free Qt Foundation designed to keep Qt open source. Distros will compile their own packages from source and so I am assuming they will not need Qt accounts as they will not be downloading Qt official “binary” releases. I think the last LTS was 5.8. Most developers will be using a much more up-to-date version as we are now on 5.14.1.

(Alf Gaida) #36

@crispinalan - you was able to find our forum in the internet - why do you claim wrong things instead of just having a look? Is using google and type Qt release history that hard?

So - 5.12 is the latest released LTS - and 5.12 will likely be in the upcoming next Debian stable release “Bullseye” (ok, it will EOL, when bullseye is released or shortly after, the not so nice thing about stable releases) - That means that any debian based Distributions will likely use 5.12 for the next few years, esp the Debian Stable and Ubuntu LTS. Much time for TQtC to rethink their decision.

(Alf Gaida) #37

@luis-pereira and @tsujan - Qt will stay open - it is impossible to close GPLed code again. There are different ways to keep the commercial releases (relative) closed. You might remember the bullshit the guys with the “secured and hardened” kernel tried (grsecurity) - and the bullshit was going to court and the result is: Grsecurtiy has to pay the costs for Bruce Perence if i remember correctly.

They tried the very same: Closed open source (of course their sources are GPLed, but they tried to prevent that customers publish the sources, a clear GPL violation) - you will find much about in th net.

TQtC can try the very same: Don’t publish the updates (sources and binaries) and just provide these things to paying customers. This would be fully GPL compatible.

Edit: Not so nice for LTS Distributions - but hey - who cares. So there is simply no need to change any license or be alarmed.

(Alf Gaida) #38

With this in mind i don’t buy any speculation about a closed source Qt - now they are aiming to one feet - aiming at two feets at the same time and hit both knees is a debian sid users privilege (closed source modules would mean: no testers, no bug reports, no developers who know and use these components - and they could not take these components from their normal development tree)

(Alf Gaida) #39

No - impossible. TQtC had to relicense the whole code to a non-free license to do so. This will not happen, as Qt has a CA (Contributors Agreement), not a CLA (Contributors License Agreement) - The major difference is that with a CA the Contributors has to agree with the license change. With a CLA not - in case of a CLA the company could do so.

(Pedram Pourang) #40

@agaida, I agree.