AppleScript: The Definitive Guide, 2nd Edition

Application

The reasons why an application might want to employ AppleScript are the same as the reasons why anyone else would—the application wishes to communicate with some other application by way of Apple events (see "Is This Application Scriptable?" in Chapter 1). It is possible to write an application that forms and sends raw Apple events directly, without using AppleScript; but AppleScript makes the task much easier for the developer of an application, just as it does for anyone else.

To write an application that uses AppleScript, you don't have to be a professional developer who spends 15 hours a day at the computer and wears a beanie with a propeller. (Of course, the beanie can't hurt, either.) In fact, writing an AppleScript application could be as simple as saving a script from a script editor application. It may be useful to distinguish three different "levels" of application into which AppleScript can be incorporated: an applet , an AppleScript Studio application, and a standard compiled application that happens to call AppleScript. I'll just briefly survey all three levels here; the first two are revisited in more detail in Chapter 27.

Applet

An applet is just a compiled script saved with a tiny application framework wrapped around it. This application framework is just sufficient to turn the script into a stand-alone application. You can make an applet very easily: save your script from within a script editor application, and as you do so, choose to save it as an Application. ...