From The Register yesterday.
The physics bods at Oxford have produced an x86 emulator written entirely in Java, and have put up a demo of it that runs in a browser which boots and has several runnable games in the emulated C: drive. Not clear if it will ever be freely available, though:-(. The demo is
here if you want to try it.
One of their screenshots is of DOS booting on a Nokia
Communicator .
I successfully ran up Commander Keen on it. It wasn't even particularly slow.