alt Hacker NewsI think Dave (of Dave's Garage) did this just a few months ago... I think there were some short-comings regarding wide character support (BoM detection, etc)... but it was pretty much a working Notepad.exe implementation.
FWIW, you can also get the new Edit implementation that's built with Rust and the Windows exe is 250kb...
Thought of this immediately after reading the parent comment. I was actually pretty shocked at how seamless the whole project was.