TIM BERNERS-LEE INVENTED A NETWORK-BASED IMPLEMENTATION OF THE HYPERTEXT CONCEPT (WWW.)

Date: 01/01/1989HyperText is a way to link and access information of various kinds as a web of nodes in which the user can browse at will. It provides a single user-interface to large classes of information (reports, notes, data-bases, computer documentation and on-line help).

Hypertext concepts

The principles of hypertext, and their applicability to the CERN environment, are discussed more fully in, a glossary of technical terms is given in . Here we give a short presentation of hypertext. A program which provides access to the hypertext world we call a browser. When starting a hypertext browser on your workstation, you will first be presented with a hypertext page which is personal to you : your personal notes, if you like. A hypertext page has pieces of text which refer to other texts. Such references are highlighted and can be selected with a mouse (on dumb terminals, they would appear in a numbered list and selection would be done by entering a number). When you select a reference, the browser presents you with the text which is referenced: you have made the browser follow a hypertext link.

That text itself has links to other texts and so on. Clicking on the GHI would take you to the minutes of that meeting. There you would get interested in the discussion of the UPS, and click on the highlighted word UPS to find out more about it.

The texts are linked together in a way that one can go from one concept to another to find the information one wants. The network of links is called a web . The web need not be hierarchical, and therefore it is not necessary to “climb up a tree” all the way again before you can go down to a different but related subject. The web is also not complete, since it is hard to imagine that all the possible links would be put in by authors. Yet a small number of links is usually sufficient for getting from anywhere to anywhere else in a small number of hops.

The texts are known as nodes. The process of proceeding from node to node is called navigation . Nodes do not need to be on the same machine: links may point across machine boundaries. Having a world wide web implies some solutions must be found for problems such as different access protocols and different node content formats. These issues are addressed by our proposal.

Nodes can in principle also contain non-text information such as diagrams, pictures, sound, animation etc. The term hypermedia is simply the expansion of the hypertext idea to these other media. Where facilities already exist, we aim to allow graphics interchange, but in this project, we concentrate on the universal readership for text, rather than on graphics.

Applications

The application of a universal hypertext system, once in place, will cover many areas such as document registration, on-line help, project documentation, news schemes and so on. It would be inappropriate for us (rather than those responsible) to suggest specific areas, but experiment online help, accelerator online help, assistance for computer center operators, and the dissemination of information by central services such as the user office and CN and ECP divisions are obvious candidates. WorldWideWeb (or W3 ) intends to cater for these services across the HEP community.

CERN. In 1980, Berners-Lee first started work as a consultant at CERN, originally called the Conseil Européen pour la Recherche Nucleaire, and now the European Particle Physics Laboratory, but still called CERN for old time’s sake. The organization consists of many facilities located in a beautiful area in the Jura mountains on the border between France and Switzerland. It was because CERN was so large and complex, with thousands of researchers and hundreds of systems, that Berners-Lee developed his first hypertext system to keep track of who worked on which project, what software was associated with which program, and which software ran on which computers. Like the development of packet switching, hyperlinks are an idea that seemed to want to be found, with Berners-Lee independently developing his ideas within five years of Ted Nelson and Douglas Engelbart.

Berners-Lee named his first hypertext system Enquire, after an old book he found as a child in his parents house called Enquire Within upon Everything which provided a range of household tips and advice. The book fascinated young Tim with the suggestion that it magically contained the answer to any problem in the world. With the building of the Enquire system in 1980, and then the Web ten years later, Berners-Lee has pretty much successfully dedicated his life to making that childhood book real.

From 1981 to 1984, Berners-Lee left CERN and worked at Image Computer Systems as Technical Design Lead, with responsibility for real-time, graphics, and communications software for an innovative software program that enabled older dot-matrix printers to print a wide range of advanced graphics. He then rejoined CERN full-time in 1984, and almost immediately started trying to get a hypertext project approved for official funding. In March, 1989, he completed a project proposal for a system to communicate information among researchers in the CERN High Energy Physics department, intended to help those having problems sharing information across a wide range of different networks, computers, and countries. The project had two main goals:

Open design. Like Robert Kahn’s design for TCP/IP, the hypertext system should have an open architecture, and be able to run on any computer being used at CERN including Unix, VMS, Macintosh, NextStep, and Windows.

Network distribution. The system should be distributed over a communications network. However, Berners-Lee thought that there might be an intermediary period when most of the research material was carried on individual CDROM’s, which never became necessary.

Cailliau. Robert Cailliau had independently proposed a project to develop a hypertext system at CERN, and joined Berners-Lee as a partner in his efforts to get the web off the ground. He rewrote the project proposal, lobbied management for funding, rounded up programmers, collaborated with Berners-Lee on papers and presentations, and helped run the first WWW conference. Cailliau later became President of the International World Wide Web Conference Committee (IW3C2).

Web development. In the fall of 1990, Berners-Lee took about a month to develop the first web browser on a NeXT computer, including an integrated editor that could create hypertext documents. He deployed the program on his and Cailliau’s computers, and they were both communicating with the world’s first web server at info.cern.ch on December 25, 1990.

The first project Berners-Lee and Cailliau tackled was to put the CERN telephone book on the web site, making the project immediately useful and gaining it rapid acceptance. Some CERN staff started keeping one window open on their computer at all times just to access the telephone web page.

Luckily, CERN had been connected to the ARPANET through the EUnet in 1990. In August, 1991, Tim posted a notice on the alt.hypertext newsgroup about where to download their web server and line mode browser, making it available around the world. Web servers started popping up around the globe almost immediately. An official Usenet 8 newsgroup called comp.infosystems.www was soon established to share info.

Berners-Lee then added support for the FTP protocol to the server, making a wide range of existing FTP directories and Usenet newsgroups immediately accessible through a web page. He also added a telnet server on info.cern.ch, making a simple line browser available to anyone with a telnet client. The first public demonstration of the web server was given at the Hypertext 91 conference. Development of this web server, which came to be called CERN httpd, would continue until July, 1996.

In June, 1992, CERN sent Berners-Lee on a three month trip through the United States. First he visited MIT’s Laboratory for Computer Science, then went to an IETF conference in Boston, then visited Xerox-Parc in Palo Alto, California. At the end of this trip he visited Ted Nelson, then living on a houseboat in Sausalito. Interestingly, Nelson had experience with film making, Berners-Lee had experience working with lighting and audiovisual equipment in the amateur theater, and Tom Bruce, who created the first PC web browser called Cello, also worked professionally as a stage manager in the theater. Maybe these Internet techies are all really just artists at heart…

In a fateful decision that significantly helped the web to grow, Berners-Lee managed to get CERN to provide a certification on April 30, 1993, that the web technology and program code was in the public domain so that anyone could use and improve it.