You can read the main Github page here: https://github.com/kholia/OSX-KVM

It only works on Macs, it needs the toolchain and ROM I guess? Docker is just one step closer to porting it on the Windows and Linux platforms.

Personally, if I wanted to run MacOSX that badly, I'd buy a Mac Mini or the lowest-priced Mac they have. Much easier and worth it for the AppleCare and Warranty.

Edit: grammar and spelling.