Beginning AppleScript®

13.6. Open Scripting Architecture

The Open Scripting Architecture (OSA) is an Apple concept that allows applications, such as Script Editor and others, to support multiple scripting languages in a way that is independent of the actual scripting language. Under this design, a scripting language can be dynamically installed as a component on your system. As of this writing, AppleScript is the only OSA language that Apple releases with OS X.

The Script Editor application is designed to work under this OSA architecture. It really doesn't know any AppleScript at all; it just knows that AppleScript is an installed OSA component. If you look under the toolbar in your Script Editor window, you see a pop-up menu in the Navigation Bar that enables you to select any OSA component. (If you don't see your Navigation Bar, choose ViewShow Navigation Bar.) You probably see only AppleScript here. On my system, I have two additional OSA components that I can choose from: JavaScript and AppleScript Debugger, both of which are available from Late Night Software (refer to Appendix C for more information).