Holy crap I was wrong.
The emulator doesn’t have a graphical interface or X Window, but it has a command line, small C compiler, and Bellard’s emac clone. All technical jargon aside, it is rather amazing the framework of a modern operating system can be run inside of a web browser. Bellard does see a future where his Linux emulator can run DOS games and other software. Brings me back to the days of Brick-Breaker.