AppleScript is a programming language that allows Macintosh users to automate repetitive tasks and to customize application s to suit specific needs. Included in every Macintosh computer, AppleScript is an integral component of the operating system that allows technically sophisticated users (not necessarily programmers) to enhance the functionality of their computers. AppleScript programs ( applet s) perform like bot s (software robot s): once they are written they can autonomously process and manage multimedia data, including digital video, text, and Web-based material. One of the newer developments in AppleScript is a capacity for enabling distributed computing through a feature that Apple calls "program linking over IP ." Web-based program linking makes it possible for programmers to work collaboratively with other (geographically remote) Macintosh users, to control applications remotely, and to call AppleScript methods on code libraries on other machines.
An AppleScript applet can be set to execute a wide variety of tasks, such as carrying out regular data backup s, finding files over the Internet, downloading, printing, and converting file formats. AppleScript uses a messaging tool called Apple Events to communicate with the operating system and applications. Apple Events transfer data, requests, and commands between applications, networks, and the OS; the performance of these tasks is transparent to the user. The AppleScript language, which resembles English, is based on sentences and statements that are saved as script s to be read by the OS. The OS then converts the instructions in the script into Apple Event messages telling designated applications to carry out tasks. According to Apple, the scripts have the ability to "think:" they make decisions in reaction to data, documents, or situations (either based on user actions or autonomously) and respond accordingly.