The primary job of this pane is to set up your Mac to work in other languages. If you bought your Mac with a localized operating system—a version that already runs in your own language—and you’re already using the only language, number format, and keyboard layout you’ll ever need, then you can ignore most of this panel. But when it comes to showing off Mac OS X to your friends and loved ones, the “wow” factor on the Mac’s polyglot features is huge.

Details appear in The Many Languages of Mac OS X Text.