Mac OS X Lion: The Missing Manual

Auto Save and Versions

In the beginning, Jobs created the Save command—because computers were really 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’s high time the world revisit that scenario. Computers now have plenty of horsepower. They could be saving your work every few seconds, 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 Lion, Auto Save is one of the key new features.

Unfortunately, it’s available in only a few programs, at least at the outset. You’ll find it in 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. And if you’re on a tear, typing nonstop, your work is saved every 5 minutes, even while you type.

In these programs, you’ll never even see the Save command in the File menu—except in that short time before you’ve saved and named a new document for the first time. After that, the command says Save a Version, which is a different ...