If you get confused by it then that's all that needs to be said. The rest has been discussed over and over. I've dropped Qt for other front-end tech and I'm happier now.

From my perspective they spread FUD about open source licensing. QT core is LGPL3. Many applications would be fine with using LGPL3 in commercial applications. Read QT's landing page on licensing, and fossa has a good block post on requirements.

https://www.qt.io/qt-licensing

https://fossa.com/blog/open-source-software-licenses-101-lgp...

>And everytime I end up confused about it.

I think this is the point. If you're making a real application you may pay for the licensing to avoid the uncertainty/risk.

It’s LGPL mostly, with some non-core libraries that are GPL or use other licenses:

https://doc.qt.io/qt-6/licensing.html

Over the years it has been noted by many that Qt’s wording and warnings about the LGPL amount to spreading FUD or outright misinformation in what seems like an attempt to scare managers and C-suite folks into buying commercial licenses “just in case”.

Qt (the company) releases MOST of their code under open source licenses, but not all. Qt4 was LGPLv2.1, Qt5 and beyond are under LGPLv3.

In every major Qt release, there's a handful of super useful but kind of niche widgets which aren't released under open source licenses, presumably as a sales tactic as buying licenses gets you these widgets and sometimes that is cheaper than building them yourself, but unless you need these, you probably don't care about this.

Although my experience attempting to buy licenses from Qt is about a decade out of date now, the way it roughly worked was you paid a per-seat-per-year fee to get a developer license or build-machine license. Then you bought bundles of deployment licenses, and the bigger the bundle then the lower the cost per license. If you are buying a bundle of a few thousand devices then you pay more per license than if you're buying a bundle of a few million. Either way, it is a significant chunk of cash you have to front to get your block of licenses and normally embedded projects are EXTREMELY sensitive to per-unit costs.

Nothing's wrong with their licensing model, but they've been known for misrepresenting their licensing model in order to steer people towards their commercial offerings.

> And every time I google and try understand what is wrong with the licensing model. And everytime I end up confused about it. Could you kindly ELI5 me what is wrong with QT licensing model?

This right here! We customers and users alike are often confused by QTs piecemeal licensing model.

Because it’s unclear and incomplete. Always prone to some KDE whims.

A big one that I've heard, is that they are funny about you developing with it under an open source license and then buying a commercial license. I.e. if you would potentially want to use something that's under the commercial license then you need to buy it when you start development instead of when you find you want the commercial side. I don't know if this is still the case, though.

Some people don't like to pay for the work of others, while expecting to be paid for their own work.

Qt licensing is rather easy to understand.

Don't want to pay Qt? Then get the same money yourself, zero.

Want to get paid while selling a product based on Qt? Give something to Qt.