This graphic floating aroung the internet shows the evolution of the humble scroll bar since its development at XEROX in the early 1980s. It shows not only how the scroll bar looked, but how it was used. (Click on the graphic for a larger look.)
Scroll bars in the 1980s were functional but pretty ugly. Early scroll bars also let you shrink and grow a window, and it was fairly hard to understand what was really going on there. User interface design was a new art form back then, and it took a few years to understand what users really wanted.
After Steve Jobs left Apple briefly in the 1980s, he founded another company called NeXT. The NeXT computer used its own operating system and was the first to put a semi-realistic look to window elements like scroll bars. While putting the up arrow and down arrow both at the bottom was unpopular, the look of the scroll bar matured. This was the first time you saw the scroll area itself change to show you how much content there was — before that the scroll box was always the same size. There was also a little “dimple” to show users where to click and drag.
Fairly soon after that, other operating systems started getting a “touchy-feely” look to their scroll bars as well. The standard for Windows became three indented stripes in the center, as it remains today.
In the 2000s, Apple, once again helmed by Steve Jobs, continued to innovate the scroll bar, making it more abstract, first with a “jelly” look and then with a cooler grey look. When touch operating systems invaded smartphones in the late 2000s, the scroll bar got thinner and lost its arrows. Why? Unlike mouse-based operating systems, smartphone OS’s let you flick anywhere to scroll, reducing the scroll bar to a simple indicator instead of an active control element.
It’s always fun to go back and look at old operating systems to see how far we’ve come, and who knows what the next iteration of the scroll bar will be?