The keyboard also added a Compose key.

Thorn may also be accessible by copy-and-pasting from a character map, through changing the keyboard layout or through a compose key.

Another option is to use a keyboard layout that supports the Compose key (usually mapped to the right alt or to one of the windows keys).

On Plan 9 systems, an en or em dash may be entered by pressing the Compose key (usually left Alt), followed by typing or respectively.

A Compose key can be characterized as a generic dead key that may in some systems be available instead of or in addition to the more specific dead keys.

Under some Linux distributions, such as Red Hat and its derivatives, the left command key performs the function of the Meta key and the right one the Compose key.

This use of dead keys enables one to type a wide variety of precomposed characters that combine various diacritics with either uppercase or lowercase letters, achieving a similar effect to the Compose key.

On UNIX-based systems using Screen or X with a Compose key enabled, it can be produced by composing : (colon) and - (minus), though this is locale- and setting-dependent.

On a Linux system supporting the Compose Key, an interrobang can be produced by pressing the compose key followed by the exclamation point and the question mark; reversing the order creates the inverted interrobang.