Yeah, I'm genuinely surprised that "four native developers" didn't realize that there is one native language which works great on all three platforms, and has direct bindings to all of the platform UI toolkits...
There isn't one that I know of. A language like c++ though would compile to a native library on each platform and allow them to share logic between 3 front ends in the same or a very similar language.
That's mostly what I meant. I don't particularly think it's a good idea to share UI code between platforms as different as macOS and Windows. I'm sure there will be serious integration regressions with the new version.
You mean several native languages with multiple multi-platform ways to create native UI.
The only env. i know is Lazarus-ide and Freepascal