From elsewhere (site is down for me):

> jpro is a new technology which brings Java back into the browser — without Java Plugin. To achieve that, jpro runs JavaFX on the server and maps its scenegraph directly into the browser.

JavaFX is the most recent of the standard GUI libraries for Java. Seems like the Java all runs server-side, but it is effectively using a display device which is "send draw commands via a websocket to a JavaScript driver running in a browser". It's sort of an ingenious idea.

I assume the target market here is companies which already have custom desktop applications written with JavaFX, and want to make them available remotely. This is competing with remote desktop solutions, not React, wasm, etc.

A Swing version of the same idea: https://jetbrains.github.io/projector-client/mkdocs/latest/

It sounds a lot like Eclipse RAP / RWT which is basically swt in the browser. The biggest downside is that every user has a heavyweight session on the server that holds all the UI state. I think Vercel is also a bit similar to this model.

I used a graph analysis app ~2011 that communicated with the server over zmq and rendered via lwjgl. At the time, and perhaps even now, it wouldn't have been reasonable to expect adequate performance if all the results of interactive manipulation were executed on the client hardware. Which was unfortunate for me since I'd also spent a few weeks writing code to visualize the same data, and it was definitely a 'works on my machine' application.

I've considered revisiting the problem, but probably not following the implementation discussed here.

> I have looked around the website and I really have no idea what this is.

Judging from the browser developer tools, something that (very slowly) sends the client stuff via a socket.

The calendar demo I tried was quite slow as well.