Haxe can do it as well.

Though I think what really sets it apart (on the web side) is that it interops pretty well with other js libs.

I think what sets it apart is the interopability with it's current targets. Really slick

Edit:fixed typo

> C/C++ can do that if you accept Emscripten.

Yeah, pls no.

> Java can do that if you accept GWT.

Yeah, I don't. Google abandoned it, you should too.

Still, they count as 'precedents'.

Precedents are nice and all but I want something I can ship stuff in.

Google still ships stuff using GWT - they just talk about it much.

They maintain legacy stuff written in GWT, I dont know any new projects that use it.

Vaadin is built on GWT and seems quite alive. https://vaadin.com/

Vaadin is doa. It’s not a spa which means it will be dead in idk three years. People love that interactivity.