In the beginning, Jobs created the Save command—because computers were slow.
Every time you saved, your work was interrupted for a few seconds (or a lot of seconds) as the very slow program on your very slow computer saved your work onto a very slow floppy disk.
And that, ladies and gentlemen, is why most programs still don’t autosave: because the interruptions were just too annoying.
Apple figured it was high time the world revisit that scenario. Computers now have plenty of horsepower. They could be saving your work continuously, and you’d never even know it. Why shouldn’t all programs save your work as you go, automatically and invisibly? As long as you also have the option to rewind and take your document in a different direction, what could possibly be the harm?
And so it is that, in OS X today, Auto Save is here. Unfortunately, it’s available in only a few programs. You’ll find it in Apple’s showcase programs: Pages, Keynote, Numbers, Preview, and TextEdit.
In these programs, your document is saved every time there’s even the tiniest pause in your typing or working—in the background. No progress bar, no interruption. If you quit or close the document without remembering to save, no problem: Your work will be there when you open the document again later.
“But wait a minute,” cry the masses—“I like being able to close a document without saving changes! Sometimes all I wanted to do was fool around, play ‘what-if’ games—and then close it without saving changes!” ...