I have started using Avalonia, and even though I am still learning, I am very satisfied with it. There are growing pains obviously, but as you said, I have no confidence in Microsoft UI frameworks.

Correct me if I 'm wrong, but I think it’s still the same situation since January 2020: the long-term-supported (LTS) releases are available to commercial licensees only and KDE supports collections of patches for Qt LTS releases. Which is a hassle for sure. But nothing has changed because a fork of Qt (worst case scenario) would demand massive manpower from KDE.

And the KDE Free Qt Foundation exists, so the Qt Company can’t close down the framework.

The Foundation has license agreements with The Qt Company, Digia and Nokia. The agreements ensure that the Qt will continue to be available as Free Software. Should The Qt Company discontinue the development of the Qt Free Edition under the required licenses, then the Foundation has the right to release Qt under a BSD-style license or under other open source licenses. The agreements stay valid in case of a buy-out, a merger or bankruptcy.

My bad, the link I sent was not about NativeAOT, just bundling all the dependencies together (also, it’s 4 years old). After a quick search, here’s a recent SO question that mentions that you can build .exe files

As for the filesize… please recheck the post under which we are commenting. :D

Does it effectively output a single binary?

Yes, that’s one of the points of NativeAOT, a self-contained single binary, exactly as Go does it.

Does it create some kind of clusterf*k and awkward packaging formats like other MS solutions such as UWP?

No, you can create .exe files.

Will it actually be deployable to a random fresh install of Debian 12 or Windows 10?

Yes, NativeAOT supports Windows, Linux and MacOS, x64 and Arm64.

What about compatibility with older systems?

Not sure about that, I suppose it depends on the targets each .NET version support. For example, .NET 8 will drop RHEL 7 and only RHEL 8 and later.

And to play devil’s advocate: this won’t work for all existing .NET applications. If you use reflection (which is AOT unfriendly), chances are that you will have to rework a ton of stuff in order to get to a point where NativeAOT works. There’s a middle solution though, called ReadyToRun, which has some advantages compared to running fully with the JIT compiler.