SK8
Encyclopedia
SK8 was a pioneering multimedia authoring environment developed in Apple's Advanced Technology Laboratory from 1988 until 1997. The original motivating idea for SK8 was to realize a development environment that would be easy to learn and that would help people to create applications by simply drawing (visual programming).
SK8 was designed for rapid development of customizable and extensible media authoring tools and titles. SK8 was a proprietary, internal development tool used by Apple designers and engineers — it was not an Apple consumer product. SK8 has been used as a tool to prototype new ideas and products, as well as a testbed for advanced research into authoring tools and their use. The goal of SK8 has been to enable productivity gains for software developers by reducing implementation time, facilitating rapid prototyping, making development fun, and supporting cross platform development and providing output to multiple runtime environments including Java. SK8 was successfully used to create rich media tools and titles simply and quickly.
The scripting language, graphics system, application framework, user interface, and various editors are explained in the User Guide.
SK8's scripting language was the first prototype implementation of AppleScript; later on it was renamed SK8Script. One of the major uses of the system was by Apple's QA group to create an automated black-box testing system. 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. SK8's scripting technology was transferred to Kaleida (a joint Apple/IBM
venture), and many projects. Outside Apple, SK8 has been seeded to over one hundred sites for evaluation and prototyping.
SK8 developers have created projects in a matter of hours. SK8 can be used to create tools designed to address specific needs. For example, media producers could create projects with time-based, event-driven and interactive book/movie sections thus adding depth and richness not available in today's authoring tools.
, which at that time supported a maximum of 8MB main memory. The name of the project probably derived from his interest in skateboard
ing.
Apple was the ideal place to start this work. HyperCard
, with its direct manipulation interface
and scripting language, was about to ship. While HyperCard was great for simple applications built by end users, it was too restrictive for professional programmers to use and its programming paradigm (i.e., stacks of cards) was fixed. One of the guiding questions for SK8 was how to extend these benefits to the wider programming community.
The first part of the work was devoted to developing a powerful, yet simple object system. The result was MacFrames, a very rich and powerful frame
/object system. The main research focus was flexibility: to allow experimentation with object models in order to find an optimal object kernel for SK8. MacFrames was so flexible that by setting a myriad of preferences it 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 simple and elegant model that is in SK8 today.
With this version of the object system in place, we started to work on the graphics and UI side of the system. The early SK8 graphics system used a metaphor slightly extending HyperCard (e.g., cards but with multiple layers instead of single fixed backgrounds). Around this time, the original version of SK8Script, a prototype for the first specification of the AppleScript
language, was extended to a fully object-oriented scripting language based on the SK8 object model. A number of researchers in the Advanced Technology Group
began to use SK8 for their projects, providing timely and intimate suggestions to improve the system. Certain universities and corporation fans began to participate: they either used SK8 as a research tool or examined it to provide detailed feedback to us.
In 1992 and 1993, to incorporate the necessary design changes while maintaining the system's elegance, we re-implemented SK8 from the ground up, resulting in the current SK8 architecture. The object system was reimplemented by manipulating the kernel of the newly acquired Macintosh Common Lisp
. The graphical library and event systems now used a containment approach and conventions based on generally useful defaults. The SK8Script debugger was completed and the compiler and runtime performance improved. An object store was added to the system. The SK8 Project Builder was created to provide a very rich set of direct manipulation tools, including tools for building browsers by visual means (e.g., wiring components, expression constraints by sliders and knobs).
A development team was assigned to investigate the possible productization of SK8; this team consisted of Philip McBride, Chris Flick, and Ken Dickey.
Jim Spohrer
, Stephanie Houde, Alan Peterson, Matthew MacLaurin, David C. Smith
, Allen Cypher, Mikel Evins, Don Tillman, Steve Seitz, and Royston Sellman provided design ideas and/or code.
Larry Tesler
, Jim Spohrer
, Mark Miller
, Steve Weyer, and David Nagel
sponsored and shepherded the project through both tumultuous and tranquil times at Apple.
SK8 was designed for rapid development of customizable and extensible media authoring tools and titles. SK8 was a proprietary, internal development tool used by Apple designers and engineers — it was not an Apple consumer product. SK8 has been used as a tool to prototype new ideas and products, as well as a testbed for advanced research into authoring tools and their use. The goal of SK8 has been to enable productivity gains for software developers by reducing implementation time, facilitating rapid prototyping, making development fun, and supporting cross platform development and providing output to multiple runtime environments including Java. SK8 was successfully used to create rich media tools and titles simply and quickly.
The SK8 environment
SK8 features:- A prototype-based, fully dynamic object system
- An English-like scripting language supporting complex declarative operations on collections
- A general and extensive graphics and event system based on containment and sophisticated rendering
- A rich object framework with support for multimedia and for tool building, fully integrated with the operating system environment.
- A feature-rich, direct manipulation development environment
The scripting language, graphics system, application framework, user interface, and various editors are explained in the User Guide.
SK8's scripting language was the first prototype implementation of AppleScript; later on it was renamed SK8Script. One of the major uses of the system was by Apple's QA group to create an automated black-box testing system. The system was used to develop prototypes for Newton
Newton (platform)
The Newton platform was an early personal digital assistant and the first tablet platform developed by Apple, the second platform being iOS, used in the iPhone, iPod Touch and iPad. Development of the Newton platform started in 1987 and officially ended on February 27, 1998. Some electronic...
, Quicktime interfaces, interprocess communication, and was used to prototype many titles, including Stagecraft, a learning tool for children. SK8's scripting technology was transferred to Kaleida (a joint Apple/IBM
IBM
International Business Machines Corporation or IBM is an American multinational technology and consulting corporation headquartered in Armonk, New York, United States. IBM manufactures and sells computer hardware and software, and it offers infrastructure, hosting and consulting services in areas...
venture), and many projects. Outside Apple, SK8 has been seeded to over one hundred sites for evaluation and prototyping.
SK8 developers have created projects in a matter of hours. SK8 can be used to create tools designed to address specific needs. For example, media producers could create projects with time-based, event-driven and interactive book/movie sections thus adding depth and richness not available in today's authoring tools.
The story of SK8
The SK8 project was created by Ruben Kleiman when he joined Apple in 1987. He came to Apple wishing to develop a highly flexible, object-oriented user interface and multimedia development environment which could be used to create not only applications, but also high-level development environments suitable for any specific domains (e.g., training, games, planning and scheduling, accounting and finance, music theory and performance). In addition, Ruben wanted to implement this on a MacintoshMacintosh
The Macintosh , or Mac, is a series of several lines of personal computers designed, developed, and marketed by Apple Inc. The first Macintosh was introduced by Apple's then-chairman Steve Jobs on January 24, 1984; it was the first commercially successful personal computer to feature a mouse and a...
, which at that time supported a maximum of 8MB main memory. The name of the project probably derived from his interest in skateboard
Skateboard
A skateboard is typically a specially designed plywood board combined with a polyurethane coating used for making smoother slides and stronger durability, used primarily for the activity of skateboarding. The first skateboards to reach public notice came out of the surfing craze of the early 1960s,...
ing.
Apple was the ideal place to start this work. HyperCard
HyperCard
HyperCard is an application program created by Bill Atkinson for Apple Computer, Inc. that was among the first successful hypermedia systems before the World Wide Web. It combines database capabilities with a graphical, flexible, user-modifiable interface. HyperCard also features HyperTalk, written...
, with its direct manipulation interface
Direct manipulation interface
In computer science, direct manipulation is a human-computer interaction style which involves continuous representation of objects of interest, and rapid, reversible, incremental actions and feedback. The intention is to allow a user to directly manipulate objects presented to them, using actions...
and scripting language, was about to ship. While HyperCard was great for simple applications built by end users, it was too restrictive for professional programmers to use and its programming paradigm (i.e., stacks of cards) was fixed. One of the guiding questions for SK8 was how to extend these benefits to the wider programming community.
The first part of the work was devoted to developing a powerful, yet simple object system. The result was MacFrames, a very rich and powerful frame
Frame language
A frame language is a metalanguage. It applies the frame concept to the structuring of language properties. Frame languages are usually software languages.-Description:...
/object system. The main research focus was flexibility: to allow experimentation with object models in order to find an optimal object kernel for SK8. MacFrames was so flexible that by setting a myriad of preferences it was used to emulate a large variety of object systems, including IntelliCorp
IntelliCorp (Software)
IntelliCorp is a software company that provides, develops, and markets SAP application lifecycle management, business process management and data management software for SAP customers and partners...
's KEE
KEE
KEE is a frame-based development tool for Expert Systems. KEE was developed and sold by IntelliCorp. It was first released in 1983 and ran on Lisp Machines. KEE was later ported to Lucid Common Lisp with CLX...
. This research, in concert with users developing actual applications and prototypes at Apple, yielded the simple and elegant model that is in SK8 today.
With this version of the object system in place, we started to work on the graphics and UI side of the system. The early SK8 graphics system used a metaphor slightly extending HyperCard (e.g., cards but with multiple layers instead of single fixed backgrounds). Around this time, the original version of SK8Script, a prototype for the first specification of the AppleScript
AppleScript
AppleScript is a scripting language created by Apple Inc. and built into Macintosh operating systems since System 7. The term "AppleScript" may refer to the scripting system itself, or to particular scripts that are written in the AppleScript language....
language, was extended to a fully object-oriented scripting language based on the SK8 object model. A number of researchers in the Advanced Technology Group
Advanced Technology Group
The Advanced Technology Group was a corporate research laboratory at Apple Computer from 1986 to 1997. ATG was started by Larry Tesler in October 1986 to study long term research into future technologies that were beyond the time frame or organizational scope of any individual product group. Over...
began to use SK8 for their projects, providing timely and intimate suggestions to improve the system. Certain universities and corporation fans began to participate: they either used SK8 as a research tool or examined it to provide detailed feedback to us.
In 1992 and 1993, to incorporate the necessary design changes while maintaining the system's elegance, we re-implemented SK8 from the ground up, resulting in the current SK8 architecture. The object system was reimplemented by manipulating the kernel of the newly acquired Macintosh Common Lisp
Macintosh Common Lisp
Macintosh Common Lisp is an implementation and IDE for the Common Lisp programming language. Various versions of MCL run under Mac OS and Mac OS X....
. The graphical library and event systems now used a containment approach and conventions based on generally useful defaults. The SK8Script debugger was completed and the compiler and runtime performance improved. An object store was added to the system. The SK8 Project Builder was created to provide a very rich set of direct manipulation tools, including tools for building browsers by visual means (e.g., wiring components, expression constraints by sliders and knobs).
SK8 personnel
Chronologically, the core SK8 team consisted of:- Ruben Kleiman: creator of SK8. Implemented versions of the object system and store, language, and graphics system. Continued developing and directed the SK8 effort until 1994.
- David Vronay: SK8 graphics and user interface.
- William Luciw: distributed object system.
- Adam Chipkin: SK8Script.
- Hernan Epelman: graphics and event system, applications framework, CASE tools, object store and various documentation efforts.
- Brian Roddy: user Interface, SK8Script, collections, CASE tools, SK8-Java generation and Java SK8 runtime library. Managed the project after 1994.
- Sidney Markowitz: object system and store, condition system, build process.
- David YostDavid YostDavid Harold Yost is an American actor and producer known for his role of Billy Cranston on the television series Mighty Morphin Power Rangers, Mighty Morphin Power Rangers: The Movie and Power Rangers Zeo.-Early life:...
: QuickTimeQuickTimeQuickTime is an extensible proprietary multimedia framework developed by Apple Inc., capable of handling various formats of digital video, picture, sound, panoramic images, and interactivity. The classic version of QuickTime is available for Windows XP and later, as well as Mac OS X Leopard and...
, OS integration.
A development team was assigned to investigate the possible productization of SK8; this team consisted of Philip McBride, Chris Flick, and Ken Dickey.
Jim Spohrer
Jim Spohrer
Jim Spohrer is a computer scientist leading the development of a new science of service systems, often known as Service Science, Management and Engineering....
, Stephanie Houde, Alan Peterson, Matthew MacLaurin, David C. Smith
David C. Smith
David C. Smith may refer to:*David Chadwick Smith , Canadian economist*David C. Smith , fantasy author*David C. Smith , American historian...
, Allen Cypher, Mikel Evins, Don Tillman, Steve Seitz, and Royston Sellman provided design ideas and/or code.
Larry Tesler
Larry Tesler
Larry Tesler is a computer scientist working in the field of human-computer interaction. Tesler has worked at Xerox PARC, Apple Computer, Amazon.com, and Yahoo!...
, Jim Spohrer
Jim Spohrer
Jim Spohrer is a computer scientist leading the development of a new science of service systems, often known as Service Science, Management and Engineering....
, Mark Miller
Mark S. Miller
Mark S. Miller is an American computer scientist. He is known for his work as one of the participants in the 1979 hypertext project known as Project Xanadu; for inventing Miller Columns; as the co-creator of the Agoric Paradigm of market-based distributed secure computing; and the open-source...
, Steve Weyer, and David Nagel
David Nagel
David Nagel has held executive positions in a wide variety of technology companies and organizations.He was named CEO and elected to the board of directors of PalmSource in December 2001, and served in this position until May 22, 2005....
sponsored and shepherded the project through both tumultuous and tranquil times at Apple.
External links
- SK8 Source Code, mirror of Apple's research FTP server