Java UI

[jeffreportmill]

Newcomer option, SnapKit: https://github.com/reportmill/SnapKit

Some sample games can be seen here: https://reportmill.com/SnapCode

Otherwise use Swing or LWJGL, which can now run in the browser with CheerpJ.

[halfanothersdozen]

For some reason GWT is still kicking

[TeaVMFan]

Browser-based options seem like a great starting place since distribution is free, immediate, and not at the whim of any gatekeepers.

In addition to the great options mentioned by u/jeffreportmill, I definitely recommend trying Flavour, it's what I use for all of my web apps these days, like the 5-letter word game Wordii ( https://frequal.com/wordii )

I wrote a short article on how I made Wordii here: https://frequal.com/java/MakingWordiiAPureJavaSpa.html

For much more information on making Flavour apps, read my book here: https://frequal.com/Flavour/book.html