AppleScript

• Authors: William R. Cook
• Venue: Proceedings of the third ACM SIGPLAN conference on History of programming languages
• Year: 2007

AppleScript is a scripting language and environment for the Mac OS. Originally conceived in 1989, AppleScript allows end users to automate complex tasks and customize Mac OS applications. To automate tasks, AppleScript provides standard programming language features (control flow, variables, data structures) and sends Apple Events to invoke application behavior. Apple Events are a variation on standard remote procedure calls in which messages can identify their arguments by queries that are interpreted by the remote application. This approach avoids the need for remote object pointers or proxies, and reduces the number of communication round trips, which are expensive in high latency environments like the early Macintosh OS. To customize an application that uses AppleScript's Open Scripting Architecture, users attach scripts to application objects; these scripts can then intercept and modify application behavior. AppleScript was designed for casual users: AppleScript syntax resembles natural language, and scripts can be created easily by recording manual operations on a graphical interface. AppleScript also supported internationalization in allowing script to be presented in multiple dialects, including English, Japanese, or French. Although the naturalistic syntax is easy to read, it can make scripts much more difficult to write. Early adoption was hindered by the difficulty of modifying applications to support Apple Events and the Open Scripting Architecture. Yet AppleScript is now widely used and is an essential differentiator of the Mac OS. AppleScript's communication model is a precursor to web services, and the idea of embedded scripting has been widely adopted.