Re: so much for macs...back to PCs
[URL]http://en.wikipedia.org/wiki/Option_key[/URL]
The Option key in a Mac operating system functions differently from the Alt key under other [URL="http://en.wikipedia.org/wiki/Unix-like"]Unix-like[/URL] systems or [URL="http://en.wikipedia.org/wiki/Microsoft_Windows"]Microsoft Windows[/URL]. Most notably, it is not used to access menus or hotkeys, but is instead used as a modifier for other command codes, and also to provide easier access to various [URL="http://en.wikipedia.org/wiki/Diacritic"]accents[/URL] and symbols.
[URL="http://en.wikipedia.org/wiki/Apple_Inc."]Apple[/URL] commonly uses the symbol ⌥ ([URL="http://en.wikipedia.org/wiki/Unicode"]U[/URL]+2325, 8997 in decimal) to represent the option key. This symbol represents a [URL="http://en.wikipedia.org/wiki/Microswitch"]microswitch[/URL], allowing the current to go one of two directions.
From 1980 to 1984, this key was known as the [B]closed apple key[/B], and had a black line drawing of a filled-in apple on it. (See [URL="http://en.wikipedia.org/wiki/Command_key"]command key[/URL] for information about the history and the "open apple".)
[URL]http://en.wikipedia.org/wiki/Command_key[/URL]
The Command key has a single purpose: allowing the user to enter keyboard shortcut commands to [URL="http://en.wikipedia.org/wiki/Graphic_User_Interface"]GUI[/URL] 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, and many other shortcuts are standardized (Find, Show Fonts). If an application needs more shortcuts than can be obtained with the twenty-six letters of the [URL="http://en.wikipedia.org/wiki/Latin_alphabet"]Latin alphabet[/URL], double modifiers such as Command+Option are used.
One advantage of this scheme, as contrasted with the [URL="http://en.wikipedia.org/wiki/Microsoft_Windows"]Microsoft Windows[/URL] mixed use of the Control and Alt keys, is that the [URL="http://en.wikipedia.org/wiki/Control_key"]Control key[/URL] is reserved entirely for its original purpose: entering [URL="http://en.wikipedia.org/wiki/Control_character"]control characters[/URL] in [URL="http://en.wikipedia.org/wiki/Terminal"]terminal[/URL] 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 [URL="http://en.wikipedia.org/wiki/Option_key"]Option key[/URL], serves as a modifier both for entering keyboard shortcuts and for typing text—it is used to enter foreign characters, typographical symbols, and other nonstandard characters.