[foresto]

It's worth noting that some cross-platform toolkits are non-native in the strict sense, but mimic each platform's native controls.

This is harder to get right than one might think; small differences in text rendering look very much alien to me, and user input handling that isn't exactly the same as the platform's native conventions will make me stumble every time I perform common operations.

In my experience, Qt does an excellent job with this. It's not technically native (except on KDE and other Qt-based desktops), but it looks and feels right, or so close that I find it comfortable and well integrated with the rest of each platform I've tried. I haven't found any other cross-platform toolkit to match Qt in this area, so that's what I use for now.

Some day, I hope we'll see an alternative that accomplishes this at least as well as Qt, while being more flexible to license, easier to bind to other languages, and better at memory safety. (It's written in C++.) There seems to be renewed interest in GUI toolkit development lately, perhaps fueled by the excitement for newer languages like Zig and Rust, so perhaps I'll get my wish.