Worth noting, mg has long been included in OpenBSD as the default Emacs-like editor, and now plays the same role in Mac OS. (I’m not sure if Apple distributes the same branch as the one maintained in OpenBSD, though.)
Wow. I didn't even know this mg existed and see it's installed already on Catalina. I love discovering new stuff like this!
Alongside the well-known ones, and Zile, another GNU text editor is Moe.
zile is great, it's only major problem being lack of Unicode support