[MayeulC]

Only for Emacs users. Vim users generally replace it with Escape.

[bombela]

Except that vim was designed on a keyboard with the Ctrl key at the place of your current capslock (for most keyboards, Japanese still have Ctrl at the "right" plac).

[vasac]

Why not both ;) - ESC when tapped, CTRL as a modifier key when pressed together with some other key.

[MayeulC]

Good idea! Though aborting a Ctrl-C could close a dialog window :/

[pxx]

I'm a vim user and replace it with Ctrl. It's much more useful and you can use ^[ to get Escape.