Emacs: What is Meta Key

By Xah Lee. Date: 2022-09-28.

What is meta key

The Meta key is a key on Lisp Machine Keyboards in the 1970s and 1980s.

lisp-machine-keyboard-2-left — Symbolics's Lisp Machine keyboard PN 365407 Rev C. (Photo by Joey Devilla [https://www.globalnerdy.com/2009/02/05/hacklabtos-lisp-machine-keyboard/]. Used with permission.)

Where is meta key

Microsoft Windows → the Alt is meta key, by default, in GNU Emacs.
Linux → the Alt is meta key, by default, in GNU Emacs.
Mac → ⌥ option or ⌘ command is meta key, depending on which emacs distribution you are using.

Syntax of meta key

In emacs documenation, the Meta key's notation is M-. For example, M-x means Meta+x.

History of Meta Key

Emacs, Change Keys