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SK8 (pronounced "skate") was a multimedia authoring environment developed in Apple's Advanced Technology Group from 1988 until 1997. The project's goal was to allow creative designers to create a complex, working application. The main components of SK8 included the object system, the programming language, the graphics and components libraries, and the Project Builder, an integrated development environment. It was described as "HyperCard on steroids". For much of its history, SK8 remained a research project, and inspired a number of other Apple projects like AppleScript, as well as seeing use as a prototyping platform. Although around 1993 a team was assigned by the Apple Product Division to release a SK8 runtime, the limitation of the Mac's capabilities as well as the shift to the PowerPC chip made such a large project intractable. With the bulk of the original vision completed and no easy path to release as part of MacOS, active development ended in 1996-1997, and the Macintosh Common Lisp source code for the entire project was released to the public in 1997. == History == The SK8 project was created by Ruben Kleiman when he joined Apple in 1987. He had come to Apple to develop a flexible, object-oriented user interface and multimedia development environment. The name of the project derived from his interest in skateboarding.〔The application splash screen prominently features a skateboard.〕 Coincidentally, at this time the HyperCard, with its direct manipulation interface and scripting language, was about to ship. While HyperCard was great for simple applications it used a limited interaction model - the "stacks" of cards" - that limited its potential applicability. SK8 attempted to extend these benefits to a wider programming role. Early work on what would become SK8 focused on infrastructure rather than visual programming. Kleiman's first effort was a dynamic, prototype-based object system, MacFrames, a frame/object system with plug-ins for inference engines. Through preferences settings, MacFrames was used to emulate a large variety of object systems, including IntelliCorp's KEE. This research, in concert with users developing actual applications and prototypes at Apple, yielded the object model used in SK8. MacFrames was developed in Coral Lisp, which was acquired by Apple and became Macintosh Common Lisp. The Macintosh at that time had no generalized inter-process communication (IPC) system. Kleiman created an IPC init for the Mac to allow MacFrames to communicate with other processes, in particular, HyperCard. This allowed HyperCard to 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. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「SK8」の詳細全文を読む スポンサード リンク
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