Ah, I see. Not as native web application, though.
They’re using Alpine Linux, install X and Openbox and Xvnc and serve KasmVNC via Nginx and connect via KasmVNC to that X instance. LibreOffice is started in fullscreen and looks like a slightly blurry web application.
But in reality it is just a regular desktop installation with some extra things.
@[email protected], maybe this is a solution? I wouldn’t recommend it because it’s not really a web-based document editor.
Usually you just see LibreOffice and nothing else, so it’s fine, I guess. Not a web-based editor, but usable.