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


There is an article in the latest edtion of Full Circle issue 153 entitled LTS versions of Qt will be available only under a commercial license. It states that this could have significant impact on communities and distributions using Qt. The full details are here. Can anyone clarify the situation?

(Pedram Pourang) #2

I just don’t understand why they rationalize it by telling, “We are making this change to encourage open-source users to quickly adopt new versions.” As if open-source users need anyone to tell them what’s good for them. Gnome attitude has come into Qt? If so, we might see more decline in Qt’s quality…


The article suggests that there might be an open-source version but is quite clear that

even small businesses are going to be expected to cough up.

Makes me wonder if its time to find a different graphics engine.

Maybe that’s why I’ve got a pile of qt packages that are being held back in the

update routine as well.


(Pedram Pourang) #4

You mean “toolkit”.

As for me, I won’t return to GTK; it’s worse – actually it’s the worst. If they ruin Qt, there are lots of things to do other than computer programming :wink: But it’s too soon to have a realistic prediction.



      [Pedram Pourang](

    February 1

I just don’t understand why they rationalize it by telling, “We are making this change to encourage open-source users to quickly adopt new versions.” As if open-source users need anyone to tell them what’s good for them. Gnome attitude has come into Qt? If so, we might see more decline in Qt’s quality…

So what options are there for the dev team? AIUI LXQT is quite tightly tied to Qt.

gtk is presently causing enough other issues here. Are there any other options



I wasn’t trying to suggest using GTK. Just wondering about any other options.

(Pedram Pourang) #7

I don’t think anything will happen to LXQt. We don’t need LTS or Qt’s binaries.

Only EFL (Enlightenment’s toolkit) comes to my mind. But I don’t mean that for LXQt.

Frankly, I’ll be happy if they make Qt Quick, QML and Qt Creator closed-source as soon as possible. But I don’t think that’ll happen.

EDIT: Oh, I meant Qt Creator, not Qt Designer.

(jwh) #8

It seems clear from the announcement: "Starting with Qt 5.15, long term support (LTS) will only be available to commercial customers. This means open-source users will receive patch-level releases of 5.15 until the next minor release will become available. This means that we will handle Qt 5.15 in the same way as e.g. 5.13 or 5.14 for open source users.

If there are issues that would prevent the use of the latest release, there will be patches available even if we do not create new full patch releases for that version anymore.

We are making this change to encourage open-source users to quickly adopt new versions."

So I guess it would affect distributions that stick to old versions forever, e.g. Debian. Rolling dists e.g. Arch will be unaffected.

(Pedram Pourang) #9

Yes, it might affect Debian stable/old-stable users to some extent and also Debian as a distro. However, on the one hand, Debian’s default DE has never been Qt-based, so I don’t think it’ll be important; on the other hand, a recent Qt version is always the best choice for Qt users and Debian provides it.


[dabeegmon] Are there any other options available?

For C++ programmer a possible alternative to Qt is the wxWidgets framework which is GPL. Its uses native available components for the OS and so if an application is written for Linux I assume it will use gtk controls. It is mature and maintained by an active community.

If Qt, Qt Quick, QML and Qt Creator were made closed-source then a commercial license would cost $5508 per year ($499 for start ups).

(Pedram Pourang) #11

IMHO, there’s nothing to worry about. Apparently, Qt needs money and their decision seems to be the best way of providing it. If it results in a better quality for Qt, it’ll be good for LXQt and KDE.

There might be one problem for KDE: If I recall correctly, KDE has an LTS version. LXQt doesn’t.

As for Qt Quick, QML and Qt Creator, I was joking – I hate them.

Really, I see no problem.


Hum… I hope so. Have you seen this where the Krita founder talks about the Qt’s recent announcement

(Pedram Pourang) #13

I think it’s a little pessimistic but has good points too. He’s absolutely right when he says, “… because Qt 5.13 turned out to be very, very buggy,” although he may not know that Qt 5.14 isn’t better.

The way I see it, based on writing codes:

Since its version 5.0, Qt started to have serious bugs that are never fixed. Sometimes a bad bug is fixed but another bad bug is introduced. I know that first hand because I’ve tried to add workarounds for Qt bugs to my apps; there have been so many and they never end.

So, IMO, there should be a big problem in how Qt is being developed starting from version 5.0. If it’s about money, the recent decision might solve the problem. If it’s about management, nothing will happen. We’ll see soon.

However, LXQt won’t be affected because (1) we don’t have LTS versions and (2) and I can’t imagine how Qt’s quality could get worse than it is now.

And please don’t get me wrong. When I mention Qt’s bad quality, I compare it with Qt itself, when its main version was 4. Qt is still far better than GTK, IMO; GTK has been a total mess since V3.0 and you don’t need a strong imagination to know that it’ll get messier.

(Luís Pereira) #14

I don’t see a major issue, for LXQt, for the near and medium term. We don’t have LTS releases, so we are in a sense, shielded from it.

Don’t get me wrong, I don’t like it, specially the given reasons to do the changes. As always, time will be judge of such changes.


Thank you for your responses (to all the dev team reponders)!

I was inquiring because it seems like so much open source software is seeing the need to ‘monetize’

and they’re generally not going about that in a way that makes me want to accept that need.

For myself - - - - I wish there were realistic alternatives but it doesn’t sound like there are

many - - - if any.



As I said and IMO a cross platform alternative to Qt is wxWidgets. However, things are different when coding C++ applications with wxWidgets. For example, there is no int main() function but a starting (launcher) class with an OnInit() function and wxWidgets uses macros a lot. The main frame (window) is the parent in a parent-child relationship with its components and has to be initialised to nullptr. As a programmer you are responsible for the binding of events with components such as using a macro to declare an event table and another macro to link a component ID (which you define) to an event handler function. Like Qt there are what they call sizers to automatically place components into say grid positions i.e. sizers describe the relationship between a parent and its children components. Generally you hand code the GUI yourself using the API documentation but there are GUI editors such as wxCrafter which comes with the latest release of CodeLite and wxFormBuilder. These generate code from the GUI design. I am not going to get into which framework has the better components or the better way of doing things I am just noting some of the differences.

If using a distro like Debian you should download the latest source code from wxWidgets and compile it yourself as the packages supplied by Debian are older versions.

If Qt becomes closed source I will develop any future Linux projects with wxWidgets. I agree with tsujan that this is unlikely but could the Qt Company open source the current version under a BSD license and then close source future versions with many new features especially for the embedded market (which I guess is huge for them with cars etc.) maybe under a different umbrella? I guess if this happened the current Qt framework would be forked. It looks like from the forum comments I am the only one worried about this license change issue.

Aside: The wxWindows library licence is essentially the L-GPL (Library General Public Licence) with an exception stating that derived works in binary form may be distributed on the user’s own terms. CodeLite is distributed under the terms of the GPLv2 license, with an exception for plugins. Plugins developed for CodeLite (other than the ones that are shipped with the official installer provided by the CodeLite team), are allowed to remain closed sourced and can be distributed under any license.


The license changes could be difficult for projects like Krita as I believe they sell Krita on the Windows store to generate revenue and so I assume they would technically breach the new license especially if they use the LTS version.

(Pedram Pourang) #18

wxWidgets is self-torture to me.

As a thought experiment, if I imagine that Qt has become closed-source and if I continue my addiction to programming, I might contribute to EFL; they’ll need it :wink:


Went looking (I’m a noob at the under the hood stuff on Linux - - - - grin!)

but there is a product on the wikipage called Guarana - - - - - - - - grin - - - had

some of that to drink when I was in Brazil - - - - liked it - - - - maybe the software

is as good as the drink? (LOL!!)


If you mean Guaraná DSL then it written in Java not C++. EFL looks interesting.