If you have some free time on this beautiful Wednesday, I recommend a visit to the James Friend. He ported the PCE emulator a while ago to run in the browser itself and ended up creating something fantastic.
Through your browser, you can use emulated versions of System 6 on a Mac Plus, from System 7 on a Mac Plus (here is another version with apps), from Windows 3.0 on an IBM PC / XT and the PC-DOS 5 on an IBM PC / XT (with Wolf 3D!).
The entire source code of the game is on GitHub, for anyone who wants to study it or modify it.
Alis, speaking of Wolf 3D and emulators, the Mashable showed these days that they already managed to make the classic Doom run on the new Apple TV:
And even, amazingly, on an Apple Watch:
(via The Loop)