In Emacs, what is the opposite function of other-window (C-x o)? [duplicate]

Answer 1

This is an old post, but I just wondered the same. It seems there now is a function for this in Emacs: previous-multiframe-window.

I have it bound to C-x O, as in uppercase letter o. Now I just throw in shift when I want to go backwards.

(global-set-key (kbd "C-x O") 'previous-multiframe-window)