The Command key, previously known as the Apple key, is a modifier key present on Apple Macintosh keyboards. A standard Macintosh keyboard has two command keys, one on each side of the space bar.

Early Apple computers, like the Apple IIc, had two such keys. The left one had an outlined Apple logo, the right had an opaque. The Apple Lisa had only the opaque, "black" apple. When the Macintosh was introduced in 1984, the keyboard had a single command key with a symbol reminiscent of a four leaf clover (⌘, U+2318). The "clover" also appeared in the Macintosh menus.

A few years later, keyboards like the Keyboard II reclaimed the "open" outlined apple logo together with the clover on the same key. As of 2005, the Apple command keys still use this design.

Use of the Command key

The Command key has a single purpose -- allowing the user to enter keyboard shortcut commands to GUI applications. The Macintosh Human Interface Guidelines have always recommended that developers use the Command key (and not the Control or Option keys) for this purpose. A small set of shortcuts (such as cut and paste, open and save) are standard across all applications. If an application needs more shortcuts than one alphabet-ful, double modifiers such as Command+Option are used.

One advantage of this scheme, as contrasted with the Microsoft Windows mixed use of the Control and Alt keys, is that the Control key is reserved entirely for its original purpose -- entering control characters in terminal applications. (Indeed, the very first Macintosh lacked a Control key; it was soon added to allow compatible terminal software.)

The Macintosh keyboard's other unusual modifier key, the Option key, serves as a modifier both for entering keyboard shortcuts and for typing text -- it is used to enter accented characters, typographical symbols, and other nonstandard characters.

The origin of the "clover" (⌘)

The "clover" symbol has no official name, but is often given nicknames like splat, butterfly, beanie, flower or shamrock. It is identical to the Saint Hannes cross , which is sometimes found in Scandinavia as an ornament on viking artefacts. It is used in Denmark, Norway and Sweden as a symbol of "sites of historical interest", e.g. church ruins. In Sweden, it is used as a roadsign at such places.

The ⌘ came into the Macintosh project at a late stage. The development team originally went for their old apple key, but Steve Jobs found it frustrating when apples filled up the Mac's menus next to the key commands. Since Jobs felt that this was an over-use of the company logo, he opted for a different key symbol. With only a few days left before deadline, the team's bitmap artist Susan Kare started researching for the apple's successor. She was browsing through a symbol dictionary when she came across the cloverleaf-like symbol, used in Sweden for "attractions on a campground". When she showed it to the rest of the team, everyone liked it, and so it became the symbol of the 1984 Macintosh command key.

See also

Andy Hertzfeld's story at Folklore.org