Qt 6.1 Beta 2 Released, Qt-Project.org Called For Revival

[dremon_nl]

It means that any software that is closed source and shown to have used code from open source qt would be breaking the terms of GPL license.

LGPL has a linking exception which means you can use the licensed product in your closed source application without opening it up as long as it is linked dynamically, LGPL license is mentioned somewhere and Qt sources are provided (on demand) along with your application.

[Setif]

Qt is double-licensed
GPL2/GPL3/LGPL2/LGPL3 (depend on the component) if you want to use it for free or with opensource license-compatible Projects.
Commercial if you want to use it with proprietary projects.

[lowflyer]

The commercial version of qt, which is not open source is ahead of open source one

That's not quite the case. I've worked with both versions. They're exactly the same. The "open source" bundled installers on Windows are easier to install than the commercial ones.

if you want to make a closed source program with qt, you have to buy liscence for commercial branch of qt from qt company.

That's also not quite correct. As long as you adhere to the conditions in the LGPL license (no static linking, mention of the license, provide source of qt) you can use the Qt libraries for any commercial project.

[ddriver]

Those people never cease to amaze me. QML inline components have been released for almost a year now, and Creator support for the feature was just introduced into a beta.

Who takes a full year to introduce IDE support for a new feature?

And quite expected - the feature is actually buggy. I found 2 quite prominent bugs in the one day I tried using it. One of them is actually quite severe - turns out that of the 3 JS declaration keywords, only var works in inline components, while let and const do not.

How does one let such a basic bug be introduced, and undiscovered for almost a year? Do those people even test? I'd understand if it is some corner case, rarely used and whatnot, but this is something as basic and common as a declaration, and 66.7% of it ain't working. So how does testing not catch something like that?

[ddriver]

As long as you adhere to the conditions in the LGPL license (no static linking, mention of the license, provide source of qt) you can use the Qt libraries for any commercial project.

LGPL is not prohibitive of static linking. What it mandates is that the end user should be able to relink, and that's perfectly achievable by providing object files, you don't need to use dynamic linking, you don't need to open your code.

[TemplarGR]

You don't seem to understand this open source thing too well..

No, i understand it all too well. Qt is not true opensource.

[carewolf]

No, the open source version is GPL lisenced, its code can not be bundled as closed source. The commercial version of qt, which is not open source is ahead of open source one

Ehh. The open source version is LGPL, and the commercial is not ahead. If anything the commercial one now provides you with the option of being behind with LTS versions.

[carewolf]

No, i understand it all too well. Qt is not true opensource.

Of course it is.. What part of LGPLv3 is not opensource?

You can complain about them not treating open source users as nicely as they used to, but it is fully open source..

[ddriver]

IIRC the commercial version will have features and fixes that will be withheld from the foss version. Or at the very least, the community binaries will not contain them.

[dremon_nl]

LGPL is not prohibitive of static linking. What it mandates is that the end user should be able to relink, and that's perfectly achievable by providing object files, you don't need to use dynamic linking, you don't need to open your code.

Theoretically yes, practically nobody provides a do-it-yourself commercial application to the end user along with object files, linking and packaging scripts and a detailed documentation how to relink it. For all practical purposes static linking is prohibited by LGPL.