Playground
Everything on this page runs in your browser. The panel on the right is a real X session — a pure-JavaScript X server (with the RENDER extension react-x11 draws through) composited to a canvas — and the editor holds ordinary react-x11 code, the same code you would run in node against a real display. It connects through a custom DISPLAY transport (demo/local:0), lays out with the same yoga WASM, and shapes text with bundled DejaVu faces standing in for fontconfig. Edit it, press Run, and press Share to get a link that carries the whole snippet in its query string — there is no server storing any of this.
postMessage across an iframe boundary. On a desktop the same code talks over a unix socket to a real X server — C, often GPU-accelerated — which does the compositing and glyph drawing itself. Judge the API here; judge the performance there.Hello, counter
The whole idea in twenty lines: a component with state, flexbox layout, and a :hover block that repaints without a React render. The <window> is a real X11 window — everything inside it is drawn into that window.