I think Azul is definitely promising, but it's still alpha level, when I first tried to run it on OSX Mojave I got a nice black screen: https://github.com/maps4print/azul/issues/35
The next time I ran it, it worked on release mode, but panicked on debug mode.
I've just tried again from master and it works, which is an improvement!
These projects are admirable, but people severely underestimate just how much work goes into building a true GUI solution. The insane amount of stuff required to wrap is bonkers-level crazy - you cannot easily match the millions of developer hours poured into the APIs used by MSFT/Apple/Linux, or the sheer complexity of a web browser.
You hands-down could not build Slack, Spotify and so forth in a solution like this. You would end up refactoring it very quickly when users start walking away because you can't have a feature they want (playing video, gifs, etc).
The next time I ran it, it worked on release mode, but panicked on debug mode.
I've just tried again from master and it works, which is an improvement!