be used as a visual programming front-end for MacFrames. Another goal of MacFrames was to build distributed processing right into the object system. Instead of using an RPC API, one simply set the object's property with the desired value and callback for the results. MacFrames was used by Apple's QA group to create an automated black-box testing system. The SK8 Project Builder was created to provide a rich set of direct manipulation tools, including tools for building interactive controls and general but non-invasive glueing. The builder's objective was to provide a visual/direct manipulation interface for building visual development environments. That is, the system could be used to develop completely different development environments tailored to different tasks. The first version of the SK8 graphics system was designed to extend HyperCard, allowing cards to have multiple layers rather than a single "background" template. The SK8 system was initially programmed in Lisp. This was considered too arcane for general use. Additionally, there was growing concern about the number of different languages in use at Apple. As part of a wider effort to modernize the MacOS, a new unified scripting language was desired. In 1989 Kleiman joined David Canfield Smith and Larry Tesler to design and implement the first version of AppleScript. This version of AppleScript used SK8 objects, and two later the Apple Product Division re-implemented AppleScript using AppleEvents as the glue for communicating with AppleScript objects. The original prototype was then renamed SK8Script, and was itself re-implemented in assembler in 1992. A number of researchers in the Advanced Technology Group began to use SK8 for their projects. Certain universities and corporations also began to participate. The system was used to develop prototypes for Newton, QuickTime interfaces, interprocess communication, and was used to prototype many titles, including Stagecraft, a learning tool for children. For performance reasons, in 1992 and 1993 SK8 was re-implemented from the ground up. Working at Apple's Cambridge Research Center, the Macintosh Common Lisp object store was isolated and directly hooked into SK8's store. The SK8Script debugger was re-implemented at the assembler language level (previously in Lisp) and the compiler and runtime performance improved. Description The SK8 system includes the object system, the graphics and component objects, the SK8Script language, and the Project Builder environment. Object System The SK8 object system was, like JavaScript, prototype-based, but unlike JavaScript, object properties were themselves objects. Hence, properties were not simply names that