DOOM rendered as a playable Vaadin Flow component. A NOMMU "Eternal" Linux runs fbdoom on Adrian Cable's single-instruction SUBLEQ virtual machine, compiled to WebAssembly and driven from a Web Worker that paints the framebuffer onto an OffscreenCanvas. Self-contained: the fast NOMMU engine and the compressed Linux+DOOM boot image ship inside the add-on JAR. Click the viewport to play — arrows move, Ctrl fires, Space uses, Alt strafes, Shift runs, 1-7 pick weapons, Esc opens the menu, and F1-F12 work. Input is delivered without SharedArrayBuffer, so no COOP/COEP cross-origin-isolation headers are required. First paint takes ~15 seconds behind a loading overlay.