“The Script Editor is the application used to read, write, record, and save AppleScript scripts. It is located in the AppleScript folder in the Applications folder on your hard drive. Script Editor version 2.0 has been completely re-written for Mac�OS�X and includes these new features and abilities:
* Simplified easier-to-use interface
* Find and Replace in script text
* Auto-wrapping of long script statements
* Multiple undos
* No 32K limit on script size
* New Dictionary Browser with color coding and grouped events & classes
* Application scriptability
* Contextual Menu Scripts for faster script writing
* Support for Application Services
More info and download link here.
