School of Computer Science & Information Technology

School of Computer Science & Information Technology

G6DPMM - Lecture 5G6DPMM - Lecture 5

Hypertext IHypertext I

What is Hypertext?What is Hypertext?

Hypertext / HypermediaHypertext / Hypermedia Non-linear reading and writingNon-linear reading and writing

Literary Machines!Literary Machines!

The major design paradigm in multimediaThe major design paradigm in multimedia Interconnected items of informationInterconnected items of information

Nodes (text or other media) - represent ideasNodes (text or other media) - represent ideas Interconnections are associations of ideasInterconnections are associations of ideas Hypertext models human thoughtHypertext models human thought

Hypertext is not the WWW !Hypertext is not the WWW ! WWW is a system that implements WWW is a system that implements somesome aspects of hypertext aspects of hypertext

Non-linearity!Non-linearity!

Hypertext PeopleHypertext People

Vanevar BushVanevar Bush Douglas EngelbartDouglas Engelbart Ted NelsonTed Nelson The WWWThe WWW

Tim Berner’s Lee / Robert CailliauTim Berner’s Lee / Robert Cailliau Marc AndreessenMarc Andreessen

Vanevar Bush (1890-1974)Vanevar Bush (1890-1974)

Distinguished electrical engineerDistinguished electrical engineer Developed analogue computing Developed analogue computing

machines in 1920’s and 1930’smachines in 1920’s and 1930’s

US government administrator 1939 onwardsUS government administrator 1939 onwards Senior scientific administrator during WWIISenior scientific administrator during WWII Published “As We May Think in 1945”Published “As We May Think in 1945”

Designed Memex - information management machineDesigned Memex - information management machine

As We May ThinkAs We May Think

...our methods of transmitting and reviewing the ...our methods of transmitting and reviewing the results of research are generations old and by now results of research are generations old and by now are totally inadequate for their purpose.are totally inadequate for their purpose.

V. Bush, (1945) As We May Think, section 1.

It (the human mind) operates by association. With It (the human mind) operates by association. With one item in its grasp, it snaps instantly to the next one item in its grasp, it snaps instantly to the next that is suggested by the association of thoughts, in that is suggested by the association of thoughts, in accordance with some intricate web of trails accordance with some intricate web of trails carried by the cells of the brain.carried by the cells of the brain.

V. Bush, (1945) As We May Think, section 6.

MemexMemex

Machine hypothesised in Machine hypothesised in As We May ThinkAs We May Think (never built)(never built)

Automated microfilm readerAutomated microfilm reader Stores books, images, personal records and Stores books, images, personal records and

communicationscommunications Central repository of knowledgeCentral repository of knowledge Indexes, links, trails bookmarksIndexes, links, trails bookmarks

MemexMemex

Machine hypothesised in Machine hypothesised in As We May ThinkAs We May Think (never built)(never built)

Automated microfilm readerAutomated microfilm reader Stores books, images, personal records and Stores books, images, personal records and

communicationscommunications Central repository of knowledgeCentral repository of knowledge Indexes, links, trails bookmarksIndexes, 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)Douglas Engelbart (b. 1925) Engineer / instrumentation expertEngineer / instrumentation expert Inspired by Bush to build Inspired by Bush to build interactiveinteractive

computerscomputers Augmentation of human intellectAugmentation of human intellect NLS (oN Line System) developed at NLS (oN Line System) developed at

“Augmentation Research Center” in “Augmentation Research Center” in Stamford Research Institute during 1960’sStamford Research Institute during 1960’s

Invented almost every major paradigm of Invented almost every major paradigm of multimedia - hardware and software!multimedia - hardware and software!

NLS (oN Line System)NLS (oN Line System)

First “multimedia” systemFirst “multimedia” system Experimental office systemExperimental office system Augment capabilities of knowledge workersAugment capabilities of knowledge workers FeaturesFeatures

Bitmapped ScreensBitmapped Screens MouseMouse Keyboard and Chord KeyboardKeyboard and Chord Keyboard Networking over telephone linesNetworking over telephone lines Video / audio conferencingVideo / audio conferencing

NLS ProjectNLS Project

User InterfaceUser Interface Graphical user interfaceGraphical user interface Multiple windowsMultiple windows Selectable textSelectable text Hierarchical menusHierarchical menus Word processingWord processing E-mailE-mail

Demonstrated at 1968 “Fall Joint Computer Conference”Demonstrated at 1968 “Fall Joint Computer Conference” Video available on WWWVideo available on WWW

Many of the developers subsequently moved to Xerox PARCMany of the developers subsequently moved to Xerox PARC

Augmentation SystemsAugmentation Systems Systems that augment the human intellectSystems that augment the human intellect

Improving the use made of intellectImproving the use made of intellect Get better results from any group of peopleGet better results from any group of people

NLS provides an online system for deep NLS provides an online system for deep collaborative thinkingcollaborative thinking Records who contributes what to communal thoughtRecords who contributes what to communal thought

Modern multimedia systems are heavily Modern multimedia systems are heavily influenced by this… influenced by this…

BUTBUTdiffer fundamentally – they are based around differ fundamentally – they are based around improving existing technology, Engelbart creates improving existing technology, Engelbart creates completely new technologies and paradigms.completely new technologies and paradigms.

Ted Nelson (b. 1935)Ted Nelson (b. 1935)

Philosopher/technologist Philosopher/technologist Coined the word “Hypertext”Coined the word “Hypertext”

Also many other words in hypertext Also many other words in hypertext lexiconlexicon

Project XanaduProject Xanadu The original hypertext projectThe original hypertext project 1960-today1960-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 XanaduProject Xanadu

Ted Nelson’s original vision of hypertextTed Nelson’s original vision of hypertext

Long running development project (1960’s till Long running development project (1960’s till recently)recently)

Never used, but massively influentialNever used, but massively influential

At one time commercial, code now released as At one time commercial, code now released as open sourceopen source

The Xanadu Model (1)The Xanadu Model (1)

Information stored as a connected literature rather Information stored as a connected literature rather than as “files”than as “files”

Information may be created, accessed and Information may be created, accessed and manipulated from anywhere in the world.manipulated from anywhere in the world.

Documents are permanent (nothing is deleted)Documents are permanent (nothing is deleted)

Document versions may be trackedDocument versions may be tracked

The Xanadu Model (2)The Xanadu Model (2)

Documents only exist once (no copies)Documents only exist once (no copies) People may create “virtual copies” - People may create “virtual copies” - transclusionstransclusions - -

of informationof information Rights are managedRights are managed Documents may be linkedDocuments may be linked

Links are unbreakableLinks are unbreakable Links are two-wayLinks are two-way

Tumbler codes (dotted strings of numbers)Tumbler codes (dotted strings of numbers) specify any part of any document - down to the bitspecify any part of any document - down to the bit

Major Hypertext SystemsMajor Hypertext Systems FRESS (1967)FRESS (1967)

File Retrieval and Editing SystemFile Retrieval and Editing System MainframesMainframes

ZOG (1972)ZOG (1972) MainframesMainframes

KMS (1981)KMS (1981) Knowledge Management SystemKnowledge Management System Sun/Apollo workstationsSun/Apollo workstations

Notecard (1985)Notecard (1985) Xerox PARCXerox PARC

Intermedia (1985)Intermedia (1985) MacintoshMacintosh

Guide (1986) Unix later Macintosh & Windows

Hypercard (1987) Macintosh

Microcosm (1990) Unix later Macintosh & Windows

World Wide Web (1992) Distributed

The World Wide WebThe World Wide Web

Tim Berners-Lee &Tim Berners-Lee &Robert Cailliau, CERNRobert Cailliau, CERN

ENQUIRE (1989)ENQUIRE (1989) Hypertext Documentation SystemHypertext Documentation System

World Wide Web (1990)World Wide Web (1990) Extremely simpleExtremely simple Implements a few aspects of XanaduImplements a few aspects of Xanadu Three standardsThree standards

URL URL HTTPHTTP HTML HTML

Web Browsers Web Browsers

Marc Andreessen & Eric BinaMarc Andreessen & Eric Bina Students in University of IllinoisStudents in University of Illinois Part time programmers in NCSAPart time programmers in NCSA

(National Center for Supercomputer Applications)(National Center for Supercomputer Applications) Mosaic Web Browser (1993)Mosaic Web Browser (1993)

MosaicMosaic Implements parts of XanaduImplements parts of Xanadu Integrated (inline) graphicsIntegrated (inline) graphics Multiple platformsMultiple platforms

UnixUnix WindowsWindows Macintosh Macintosh ArchimedesArchimedes

Development of Web Browsers Development of Web Browsers

NCSA MosaicNCSA Mosaic Netscape Navigator (1994)Netscape Navigator (1994)

Based upon Mosaic, written mostly by the same peopleBased upon Mosaic, written mostly by the same people Spyglass Mosaic (1994)Spyglass Mosaic (1994)

Commercial version of NCSA MosaicCommercial version of NCSA Mosaic Licensed to Microsoft - became Internet ExplorerLicensed to Microsoft - became Internet Explorer

Browser Wars!Browser Wars!

Web Browsers Today Web Browsers Today MS Internet Explorer (Windows & Mac)MS Internet Explorer (Windows & Mac) NetscapeNetscape

Commercial version defunctCommercial version defunct Mozilla (all platforms)Mozilla (all platforms)

Open source NetscapeOpen source Netscape Spin-offs - Firefox, Camino, Galeon, Skipstone, Spin-offs - Firefox, Camino, Galeon, Skipstone,

Salamander, Epiphany, K-meleon, Aphrodite, Beonex, Salamander, Epiphany, K-meleon, Aphrodite, Beonex, IBM Web Browser & many othersIBM Web Browser & many others

Opera (all platforms)Opera (all platforms) Konqueror (Unix only)Konqueror (Unix only)

Open sourceOpen source Spin off - Safari (Apple, OSX)Spin off - Safari (Apple, OSX)