When you write in a word processor or text editor on OS X, you might want the app to do more than record your words as unadorned plain text. In addition to specifying formatting (such as font style and type size), you may want to insert things like smart (or "curly") quotes and live, clickable links. You may want your spelling and grammar to be checked as you type. And you may wish to insert certain bits of text automatically, to save time.
