The original "Happy Mac" greeted users up to OS 9.

The "Sad Mac", in contrast, popped up when a major system error occurred -- its current counterpart is the rare kernel panic screen.

The wrist watch was Apple's original waiting icon. Today it has been replaced by the spinning beach ball.

This was Mac OS's trash icon until OS 9.

The first Macs didn't even have hard drives. This icon was for the disk drive.

Apple's original icon for font files.

Apple's original icon for image files.

The icon for Apple's famous paint program, which most children of the 1980s and 1990s used in elementary school.

The full Mac Paint tool set was pretty advanced for an application that now seems so antiquated.

This was the basic pencil cursor in Mac Paint.

The hand for panning across images in Mac Paint. As UI artist Susan Kare says, "The fingers are spread to suggest the way a real hand rests on a piece of paper to slide it around."

The original fill canvas can from Mac Paint lives on in some form in most graphic art software, including Adobe Photoshop.

The graffiti inspired rattle can was a spray paint tool in Mac Paint.

The bomb spelled panic in early versions of Mac OS.

It was often accompanied by a message similar to that pictured above.

Friendlier than the bomb, this was Apple's original alert man.

Claris the Cow Dog is a memorable wingding from the Cairo font that shipped with the original Mac.

Even more significant than the spotted dog is the Chicago font. Like most of the other icons in this gallery, it was designed by Susan Kare and became the system font for many iterations of Mac OS.

The command key, also known as the Apple key, was used on the first Mac in 1984 and shows up on our keyboards to this day. The symbol is commonly used in Scandinavia to indicate cultural locations and places of interest. Susan Kare found it in a symbol dictionary, and the Apple team liked it.

The trash icon in OS 9 got a significant revamp.

The OS 9 hard drive icon was revamped as well, when Apple's icon designs started going 3D.

This happy Mac first appeared in Mac OS 9, and is currently used by Apple today. You may recognize it as your Finder icon.

Whether you call it the spinning beach ball of death, rainbow wheel, or wait cursor, you know what it is. This icon replaced the wristwatch in OS X, and requires users to wait patiently while OS X figures out its problems.

The sad iPod icon uses the same face as the sad Mac, but appears when an iPod is permanently out of commission.

This is Apple's current hard drive icon, and shows how far their design team has come since 1984.