On: e is a customizable self-aware Emacs-like editor written in Chez Scheme

[gpvos]

True. ":" is the rough equivalent to M-x, though.

Also worth mentioning is Q , which puts you in ex mode, essentially just ":" prompts one after the other until you exit or issue a "vi" command to go (back) to visual mode.

And then there's open mode, but vim doesn't implement that.