School of Computer Science & Information Technology G6DPMM - Lecture 5 Hypertext I

What is Hypertext? Hypertext / Hypermedia Hypertext / Hypermedia Non-linear reading and writing Non-linear reading and writing Literary Machines! Literary Machines! The major design paradigm in multimedia The major design paradigm in multimedia Interconnected items of information Interconnected items of information Nodes (text or other media) - represent ideas Nodes (text or other media) - represent ideas Interconnections are associations of ideas Interconnections are associations of ideas Hypertext models human thought Hypertext models human thought Hypertext is not the WWW ! Hypertext is not the WWW ! WWW is a system that implements some aspects of hypertext WWW is a system that implements some aspects of hypertext

Non-linearity!

Hypertext People Vanevar Bush Vanevar Bush Douglas Engelbart Douglas Engelbart Ted Nelson Ted Nelson The WWW The WWW Tim Berner’s Lee / Robert Cailliau Tim Berner’s Lee / Robert Cailliau Marc Andreessen Marc Andreessen

Vanevar Bush ( ) Distinguished electrical engineer Distinguished electrical engineer Developed analogue computing machines in 1920’s and 1930’s Developed analogue computing machines in 1920’s and 1930’s US government administrator 1939 onwards US government administrator 1939 onwards Senior scientific administrator during WWII Senior scientific administrator during WWII Published “As We May Think in 1945” Published “As We May Think in 1945” Designed Memex - information management machine Designed Memex - information management machine

As We May Think...our methods of transmitting and reviewing the results of research are generations old and by now are totally inadequate for their purpose. V. Bush, (1945) As We May Think, section 1. It (the human mind) operates by association. With one item in its grasp, it snaps instantly to the next that is suggested by the association of thoughts, in accordance with some intricate web of trails carried by the cells of the brain. V. Bush, (1945) As We May Think, section 6.

Memex Machine hypothesised in As We May Think (never built) Machine hypothesised in As We May Think (never built) Automated microfilm reader Automated microfilm reader Stores books, images, personal records and communications Stores books, images, personal records and communications Central repository of knowledge Central repository of knowledge Indexes, links, trails bookmarks Indexes, links, trails bookmarks

Memex Machine hypothesised in As We May Think (never built) Machine hypothesised in As We May Think (never built) Automated microfilm reader Automated microfilm reader Stores books, images, personal records and communications Stores books, images, personal records and communications Central repository of knowledge Central repository of knowledge Indexes, links, trails bookmarks Indexes, links, trails bookmarks When the user is building a trail, he names it, inserts the name in his code book, and taps it out on his keyboard. Before him are the two items to be joined, projected onto adjacent viewing positions. At the bottom of each there are a number of blank code spaces, and a pointer is set to indicate one of these on each item. The user taps a single key, and the items are permanently joined [...] Thereafter, at any time, when one of these items is in view, the other can be instantly recalled merely by tapping a button below the corresponding code space. Moreover, when numerous items have been thus joined together to form a trail, they can be reviewed in turn, rapidly or slowly, by deflecting a lever like that used for turning the pages of a book. It is exactly as though the physical items had been gathered together from widely separated sources and bound together to form a new book. Extract from As We May Think

Douglas Engelbart (b. 1925) Engineer / instrumentation expert Engineer / instrumentation expert Inspired by Bush to build interactive computers Inspired by Bush to build interactive computers Augmentation of human intellect Augmentation of human intellect NLS (oN Line System) developed at “Augmentation Research Center” in Stamford Research Institute during 1960’s NLS (oN Line System) developed at “Augmentation Research Center” in Stamford Research Institute during 1960’s Invented almost every major paradigm of multimedia - hardware and software! Invented almost every major paradigm of multimedia - hardware and software!

NLS (oN Line System) First “multimedia” system First “multimedia” system Experimental office system Experimental office system Augment capabilities of knowledge workers Augment capabilities of knowledge workers Features Features Bitmapped Screens Bitmapped Screens Mouse Mouse Keyboard and Chord Keyboard Keyboard and Chord Keyboard Networking over telephone lines Networking over telephone lines Video / audio conferencing Video / audio conferencing

NLS Project User Interface User Interface Graphical user interface Graphical user interface Multiple windows Multiple windows Selectable text Selectable text Hierarchical menus Hierarchical menus Word processing Word processing Demonstrated at 1968 “Fall Joint Computer Conference” Demonstrated at 1968 “Fall Joint Computer Conference” Video available on WWW Video available on WWW Many of the developers subsequently moved to Xerox PARC Many of the developers subsequently moved to Xerox PARC

Augmentation Systems Systems that augment the human intellect Systems that augment the human intellect Improving the use made of intellect Improving the use made of intellect Get better results from any group of people Get better results from any group of people NLS provides an online system for deep collaborative thinking NLS provides an online system for deep collaborative thinking Records who contributes what to communal thought Records who contributes what to communal thought Modern multimedia systems are heavily influenced by this… BUT differ fundamentally – they are based around improving existing technology, Engelbart creates completely new technologies and paradigms. Modern multimedia systems are heavily influenced by this… BUT differ fundamentally – they are based around improving existing technology, Engelbart creates completely new technologies and paradigms.

Ted Nelson (b. 1935) Philosopher/technologist Philosopher/technologist Coined the word “Hypertext” Coined the word “Hypertext” Also many other words in hypertext lexicon Also many other words in hypertext lexicon Project Xanadu Project Xanadu The original hypertext project The original hypertext project 1960-today 1960-today Ideas described in books: Ideas described in books: Computer Lib / Dream Machines (1974) Computer Lib / Dream Machines (1974) Literary Machines (1981) Literary Machines (1981) ZigZag (current ongoing project) ZigZag (current ongoing project)

Project Xanadu Ted Nelson’s original vision of hypertext Ted Nelson’s original vision of hypertext Long running development project (1960’s till recently) Long running development project (1960’s till recently) Never used, but massively influential Never used, but massively influential At one time commercial, code now released as open source At one time commercial, code now released as open source

The Xanadu Model (1) Information stored as a connected literature rather than as “files” Information stored as a connected literature rather than as “files” Information may be created, accessed and manipulated from anywhere in the world. Information may be created, accessed and manipulated from anywhere in the world. Documents are permanent (nothing is deleted) Documents are permanent (nothing is deleted) Document versions may be tracked Document versions may be tracked

The Xanadu Model (2) Documents only exist once (no copies) Documents only exist once (no copies) People may create “virtual copies” - transclusions - of information People may create “virtual copies” - transclusions - of information Rights are managed Rights are managed Documents may be linked Documents may be linked Links are unbreakable Links are unbreakable Links are two-way Links are two-way Tumbler codes (dotted strings of numbers) Tumbler codes (dotted strings of numbers) specify any part of any document - down to the bit specify any part of any document - down to the bit

Major Hypertext Systems FRESS (1967) FRESS (1967) File Retrieval and Editing System File Retrieval and Editing System Mainframes Mainframes ZOG (1972) ZOG (1972) Mainframes Mainframes KMS (1981) KMS (1981) Knowledge Management System Knowledge Management System Sun/Apollo workstations Sun/Apollo workstations Notecard (1985) Notecard (1985) Xerox PARC Xerox PARC Intermedia (1985) Intermedia (1985) Macintosh Macintosh l Guide (1986) l Unix l later Macintosh & Windows l Hypercard (1987) l Macintosh l Microcosm (1990) l Unix l later Macintosh & Windows l World Wide Web (1992) l Distributed

The World Wide Web Tim Berners-Lee & Robert Cailliau, CERN Tim Berners-Lee & Robert Cailliau, CERN ENQUIRE (1989) ENQUIRE (1989) Hypertext Documentation System Hypertext Documentation System World Wide Web (1990) World Wide Web (1990) Extremely simple Extremely simple Implements a few aspects of Xanadu Implements a few aspects of Xanadu Three standards Three standards URL URL HTTP HTTP HTML HTML

Web Browsers Marc Andreessen & Eric Bina Marc Andreessen & Eric Bina Students in University of Illinois Students in University of Illinois Part time programmers in NCSA (National Center for Supercomputer Applications) Part time programmers in NCSA (National Center for Supercomputer Applications) Mosaic Web Browser (1993) Mosaic Web Browser (1993) Mosaic Mosaic Implements parts of Xanadu Implements parts of Xanadu Integrated (inline) graphics Integrated (inline) graphics Multiple platforms Multiple platforms Unix Unix Windows Windows Macintosh Macintosh Archimedes Archimedes

Development of Web Browsers NCSA Mosaic NCSA Mosaic Netscape Navigator (1994) Netscape Navigator (1994) Based upon Mosaic, written mostly by the same people Based upon Mosaic, written mostly by the same people Spyglass Mosaic (1994) Spyglass Mosaic (1994) Commercial version of NCSA Mosaic Commercial version of NCSA Mosaic Licensed to Microsoft - became Internet Explorer Licensed to Microsoft - became Internet Explorer Browser Wars! Browser Wars!

Web Browsers Today MS Internet Explorer (Windows & Mac) MS Internet Explorer (Windows & Mac) Netscape Netscape Commercial version defunct Commercial version defunct Mozilla (all platforms) Mozilla (all platforms) Open source Netscape Open source Netscape Spin-offs - Firefox, Camino, Galeon, Skipstone, Salamander, Epiphany, K-meleon, Aphrodite, Beonex, IBM Web Browser & many others Spin-offs - Firefox, Camino, Galeon, Skipstone, Salamander, Epiphany, K-meleon, Aphrodite, Beonex, IBM Web Browser & many others Opera (all platforms) Opera (all platforms) Konqueror (Unix only) Konqueror (Unix only) Open source Open source Spin off - Safari (Apple, OSX) Spin off - Safari (Apple, OSX)