AppleScript Editor
Script Editor is a code editor for the AppleScript scripting language, included in classic Mac OS and macOS.
AppleScript Editor provides basic debugging capabilities and can save AppleScripts as plain text, as a compiled script, as a script bundle, or as an application. AppleScript Editor also handles script dictionary files, allowing the user to see what scripting classes and commands are available for each scriptable application installed on the computer.
Prior to Mac OS X 10.3, Script Editor was developed using Carbon. 10.3 introduced a new Script Editor written using Cocoa. From Mac OS X 10.6 to 10.10, it was called AppleScript Editor. It likely regained its original name because of the introduction of JavaScript for Automation.
