Trivia time! The windows console host (conhost) provides the “UI” for nano server. Even on desktop Windows, it’s built with support for running without a window manager. The rendering engine is named “wddmcon” and it lives in our repository at [1]; it’s pretty much the most barebones console renderer we have. Reverse video and most color support were obviously[2] never implemented… even though I would have liked to s…
Nano Server uses bgfxcon exclusively, as well as some magic in a "console keyboard driver" that I didn't know we had.