WorldWideWeb: Proposal for a HyperText Project

To: P.G. Innocenti/ECP, G. Kellner/ECP, D.O. Williams/CN Cc: R. Brun/CN, K. Gieselmann/ECP, R. Jones/ECP, T. Osborne/CN, P. Palazzi/ECP, N. Pellow/CN, B. Pollermann/CN, E.M. Rimmer/ECP From: T. Berners-Lee/CN, R. Cailliau/ECP Date: 12 November 1990

HyperText 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). We propose a simple scheme incorporating servers already available at CERN.

The project has two phases: firstly we make use of existing software and hardware as well as implementing simple browsers for the user's workstations, based on an analysis of the requirements for information access needs by experiments. Secondly, we extend the application area by also allowing the users to add new material.

Phase one should take 3 months with the full manpower complement, phase two a further 3 months, but this phase is more open-ended, and a review of needs and wishes will be incorporated into it.

The manpower required is 4 software engineers and a programmer, (one of which could be a Fellow). Each person works on a specific part (eg. specific platform support).

Each person will require a state-of-the-art workstation , but there must be one of each of the supported types. These will cost from 10 to 20k each, totalling 50k. In addition, we would like to use commercially available software as much as possible, and foresee an expense of 30k during development for one-user licences, visits to existing installations and consultancy.

We will assume that the project can rely on some computing support at no cost: development file space on existing development systems, installation and system manager support for daemon software.

WorldWideWeb:

T. Berners-Lee / CN, R. Cailliau / ECP

Abstract:

Introduction

At CERN, a variety of data is already available: reports, experiment data, personnel data, electronic mail address lists, computer documentation, experiment documentation, and many other sets of data are spinning around on computer discs continuously. It is however impossible to "jump" from one set to another in an automatic way: once you found out that the name of Joe Bloggs is listed in an incomplete description of some on-line software, it is not straightforward to find his current electronic mail address. Usually, you will have to use a different lookup-method on a different computer with a different user interface. Once you have located information, it is hard to keep a link to it or to make a private note about it that you will later be able to find quickly.

Hypertext concepts

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 :

(see Fig. 1: hypertext links).

That text itself has links to other texts and so on. In fig. 1, 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

Scope: Objectives and non-Objectives

to provide a common (simple) protocol for requesting human readable information stored at a remote system, using networks;

to provide a protocol within which information can automatically be exchanged in a format common to the supplier and the consumer;

to provide some method of reading at least text (if not graphics) using a large proportion of the computer screens in use at CERN;

to provide and maintain at least one collection of documents, into which users may (but are not bound to) put their documents. This collection will include much existing data. (This is partly to give us first hand experience of use of the system, and partly because members of the project will already have documentation for which they are responsible)

to provide a keyword search option, in addition to navigation by following references, using any new or existing indexes (such as the CERNVM FIND indexes). The result of a keyword search is simply a hypertext document consisting of a list of references to nodes which match the keywords. to allow private individually managed collections of documents to be linked to those in other collections. to use public domain software wherever possible, or interface to proprietary systems which already exist.

to provide the software for the above free of charge to anyone.

The project will not aim

to provide conversions where they do not exist between the many document storage formats at CERN, although providing a framework into which such conversion utilities can fit;

to force users to use any particular word processor, or mark-up format;

to do research into fancy multimedia facilities such as sound and video;

to use sophisticated network authorisation systems. data will be either readable by the world (literally), or will be readable only on one file system, in which case the file system's protection system will be used for privacy. All network traffic will be public.

Requirements Analysis

This analysis will at first be limited to the activities of the members of the Aleph experiment, and later be extended to at least one other experiment. An overview will be made of the information generation, storage and retrieval, independent of the form (machine, paper) and independent of the finality (experiment, administration).

The result should be:

lists of sources, depots and sinks of information,

lists of formats,

diagrams of flow,

statistics on traffic,

estimated levels of importance of flows,

lists of client desires and / or suggested improvements,

estimated levels of satisfaction with platforms,

estimated urgency for improvements.

Architecture

Building blocks

A browser

it performs the display of a hypertext node using the client hardware & software environment. For example, a Macintosh browser will use the Macintosh interface look-and-feel.

it performs the traversal of links. For example, when using a Macintosh to browse on CERNVM FIND it will be the Macintosh browser which remembers which links were traversed, how to go back etc., whereas the CERNVM server just responds by handing the browser nodes, and has no idea of which nodes the user has visited.

it performs the negotiation of formats in dialog with the server. For example, a browser for a VT100 type display will always negotiate ASCII text only, whereas a Macintosh browser might be constructed to accept PostScript or SGML.

A server

it manages a web of nodes on that machine.-

it negotiates the presentation format with the browser, performing on-the-fly (or cached) conversions from its own internal format, if any..

Operation

Once the server has located the requested node, it will know from the node contents what the node's format is (eg. pure ASCII, marked-up, word processor storage and which word processor etc.). The server then begins a negotiation with the browser, in which they decide between them what format is acceptable for display on the user's screen. This negotiation will be based only on existing conversion programs and formats: it is not in the scope of W3 to write new converters. The last resort in the negotiation is the binary transfer of the node contents to a file in the user's file space. Negotiating the format for presentation is particular to W3.

Project phases

Phase 1 -- Target: 3 months from start

Browsers on dumb terminal to open readership to anyone with a computer or PC.(?)

Browsers on vt220 terminals to give cursor-oriented readership to a very large proportion of readers; A browser on the Macintosh in the Macintosh style; A browser on the NeXT using the NeXTStep tools, as a fast prototype for ideas in human interface design and navigation techniques.

A server providing access to the world of Usenet/Internet news articles. *

A server providing access to all the information currently stored on CERNVM and mentioned in the FIND index. This should include CERN program library notes, IBM and CERN CMS help screens, CERN/CN writeups, Computer Newsletter articles, etc.

A server which may be installed on any machine to allow files on that machine to be accessed as hypertext.

The ability for users to write, using markup tags, their own hypertext for help files. No other hypertext editing capability will necessarily be implemented in this phase.

A gateway process to allow access between the Internet and DECnet protocol worlds.

A set of guidelines on how to manage a hypertext server.

A requirements analysis of the information access needs for a large experiment.

Phase 2 -- Target: 6 months from start

The creation of new links and new material by readers. At this stage, authorship becomes universal.

A full-screen browser on VM/XA for those using CERNVM, and other HEP VM sites;

An X-window browser/editor, giving the sophisticated facilities originally prototyped under NeXTStep to the wide X-based community. (We imagine using OSF/Motif subject to availability)

The automatic notification of a reader when new material of interest to him/her has become available. This is essential for news articles, but is very useful for any other material.

System architect. Coordinate development, protocol definition, etc; ensures integrity of design. (50% TBL?) Market research and product planner. Discuss the project and its features with potential and actual users in all divisions. Prepare criteria for feature selection and development priority. (50% RC?)

Hyper-Librarian. Oversees the web of available data, ensuring its coherency. Interface with users, train users. Manages indexes and keyword systems. Manages data provided by the project itself. (100% KG?)

Software engineer: NeXTStep. Provide browser/editor interface under the NeXTStep human interface tools. Experiment with navigational aids. Keep a running knowledge of the NeXTStep world. (50%TBL?)

Software engineer: X-windows and human interface. Provide browser/editor human interface under OSF/Motif. Respond to user suggestion for ease of use improvements and options. Create an aesthetic, practical human interface. Keep a running knowledge of the X world. (75%RJ?)

Software engineer: IBM mainframe. Provide browser service on CERNVM and other HEP VM sites. Maintain the FIND server software. Keep up a running knowledge of the CMS, Rexx world. (75% BP?)

Software engineer: Macintosh. Provide browser/editor for the mac, using whatever tools are appropriate (Thnk-C, HyperCard, etc?). (50%RC?)

Software engineer: C. Help write code for dumb terminal or vt100 browsers, and portable browser code to be shared between browers. This could include a technical student project. (100% NP? + A.N.Other?)

2. Other resources

We feel it is important for those involved in the project to be able to work close to each other and exchange ideas and problems as they work. An office area or close group of offices is therefore required.

Each person working on the project will require a state-of-the-art workstation. Experience shows that a workstation has to be upgraded in some way every two years or so as software becomes more cumbersome, and memory/speed requirements increase. This, and the cost of software upgrades, we foresee as reasonable expenses. We imagine using a variety of types of workstation as we provide software on a variety of machines, but otherwise NeXTs. For VMS machines, we would like the support of an existing VAXcluster to minimize our own system management overheads.

We would like to be able to purchase licenses for commercial hypertext software where we feel this could be incorporated into the project, and save development and maintenance time, or where we feel we could gain useful experience from its use. (Approximate examples are: Guide license: CHF750; KMS full author license CHF1500, evaluation kit CHF100. FrameMaker: CHF2000)

We will require computing support. In particular, we will require a reliable backed up NFS (or equivalent) file server support for our development environment. We will also need to run daemon software on machines with Internet, DECnet and BITNET connectivity, which will require a certain amount of support from operators and system managers.

Future paths

The two phases above will provide an extremely useful set of tools. Though the results seem ambitious, the individual steps necessary are well within our abilities with available technology. Future developments which would further enhance the project could include:

Daemon programs which run overnight and build indexes of available information.

A server automatically providing a hypertext view of a (for example Oracle) database, from a description of the database and a description (for example in SQL) of the view required.

Work on efficient networking over wide areas, negotiation with other sites to provide compatible online information.

A serious study of the use and abuse of the system, the sociology of its use at CERN.

References