Qt costs serious money if you go commercial. That might not be important for a hobby project, but lowers the enthusiasm for using the stack since the big players won't use it unless other considerations compel them.

Depends on the modules and features you use, or where you're deploying, otherwise it's free if you can adhere to the LGPL. Just make it so users can drop in their own Qt libs.

I'm sure microsoft and slack have sufficient funds for a commercial Qt license.

QT only costs money if you want access to their custom tooling or insist on static linking. We're comparing to electron here. Why do you need to static link? And why can't you write QML in your text editor of choice and get on with life?

Some widgets and modules, like Qt Charts (or Graphs, I forget), are dual GPL and commercially licensed, so it's a bit more complicated than that. You also need a commercial license for automotive and embedded deployments.

Right but it's a perfectly functional (even remarkably feature complete) UI toolkit without the copyleft addons.

> You also need a commercial license for automotive and embedded deployments.

How does that work? The LGPL (really any OSI license) isn't compatible with additional usage restrictions.

I'm guessing some parts of code are needed to make it run on those platforms and aren't LGPL.

You generally can't adhere to the LGPL in automotive or embedded deployments: the user can't link their own Qt libs in their auto/embedded device.

Slint has a similar license

> You generally can't adhere to the LGPL in automotive

"Can't" or "won't"? The UI process is not usually the part that need certification.

> Slint has a similar license

Indeed, but Slint's open source license is the GPL and not the LGPL. And its more permissive license is made for desktop apps and explicitly forbid embedded (so automotive)

...which is the same as Flutter. Both don't use native UI toolkits (though Qt doesn't use Skia, I'll give you that (Flutter has Impeller engine in the works)). And Qt has much worse developer experience and costs money.

Qt costs money if you for some reason insist on static linking AND use all the fancy components, the core stuff is all LGPL.

Anyway it does look native and it is way faster than electron, which also doesn't look native so I don't understand why it's a problem for Qt but not for electron.