Much later, the HX DOS Extender (https://www.japheth.de/HX.html) had something vaguely similar called Win32 emulation mode. Meaning that you could load a Win32 PE image, and it could call quite a few Win32 APIs, all while running under plain DOS (in 32-bit flat mode), with HX DOS providing the implementation.
It had just enough parts of the API implemented to be able to run Quake 2 in DOS.
It had just enough parts of the API implemented to be able to run Quake 2 in DOS.