The information can be accessed by using simple
hypertext techniques, such as clicking or a highlighted phrase.
WWW is based on the client/server architecture, illustrated in Figure 1.
Figure 1 WWW Client/Server Architecture.
The client program (often called a browser) runs on the local workstation.
When a hypertext link is activated, a request is sent to the server software,
which normally runs on a remote server system. The server software (e.g.
CERN httpd) will then transfer the file to the client.
A variety of server software packages are available, including the widely
CERN and NCSA httpd servers for Unix, commercial servers (which may
be more reliable or provide additional features such as security) and
servers for Apple Macintosh and the PC.
When setting up an institutional WWW service, the following server
issues need to be addressed:
- Server hardware strategy. Will your institution run a central WWW
system, or will the server software run on a number of departmental
- Which server software?
- What server functionality will be required?
- Can the service be future-proofed, so that a change in the server
software or server hardware strategy can be made with the minimum
A variety of browser clients are available, including
When choosing a browser the following issues should be considered:
- NCSA Mosaic
- EINet (WinWeb, MacWeb)
- Enhanced Mosaic
- Lynx and DosLynx
- The ease-of-use and robustness of the browser.
- Any security implications inherent in making the browser widely
- Performance implications.
- The background of the software developer and their target audience.
- The likelihood that desirable new facilities will be included in future
Running Software On The Server
WWW can not only be used to deliver multimedia documents. The
Common Gateway Interface (CGI) is a mechanism by which software
running on the remote server can generate a virtual document. The use of CGI programs was used initially for developing searching tools.
However it is now being used for developing distributed teaching and
Running Software On The Client
A WWW server delivers a MIME document to the browser. The browser
will be configured to process MIME documents. For example HTML
documents will be displayed by the browser, whereas the JPEG MIME type
will normally be passed to an external graphical viewer. A Chemical
MIME type has been developed by Henry Rzepa (Imperial College) and
others. When such a MIME type is delivered, the browser can be
configured to pass the document to a molecular modelling program.
Figure 2 WWW MIME Types.
This mechanism enables documents to be transferred from a remote
server and passed on to an application on the local machine. New
mechanisms are under development which will enable applications on
the client to communicate with WWW browsers. The new mechanisms
include CCI (Common Client Interface) and W3A (WWW Applets).
WWW is many things to many people. It can be regarded as a system for
the academic world, for the commercial world and for the cultural and
social world. It be regarded as a distributed file viewer or as a distributed
program manager. It is also, ambiguously, referred to as the "Internet
killer application". A number of examples of the use of WWW in the
academic world are given below.
Many research papers, results, proposals, etc. are being made available on
WWW . One potential benefit of this is in making state of the art
research material available to undergraduate students.
Experimental Research at CERN.
Libraries are beginning to make material available on w. w. W. This may
provide a consistent interface between a library catalogue and other
services on WWW
This illustrates access to a backup copy of the Library catalogue at the
University of Leeds . The backup copy, held in a BRS free text retrieval
system, is accessed on WWW by using a CGI gateway.
Campus Wide Information Systems (CWISes) are being developed on
WWW. This illustrates the CWIS at the University of Bradford .
Distributed Teaching and Learning
WWW is being used to develop distributed teaching and learning systems.
The Frog Dissection Kit is one of the best known
examples of a distributed teaching application.
Frog Dissection Kit.
Students are being given the opportunity to develop their own authoring
skills. As illustrated below, Fine Arts students at the University of
Leeds write multimedia essays. The essays will be used as an information
resource by subsequent student groups.
Student Authoring Skills.
WWW is being used as a scientific visualisation tool. It may be difficult to
visualise a molecule from simple reading text and viewing a 2D image.
As illustrated below, the data used to produce the 2D image may by
retrieved and loaded into a local molecular modelling package, enabling
the molecule to be manipulated . The technique can also be used for
teaching and learning purposes.
WWW is being used to provide integration with control systems. Mark
Cox, University of Bradford has developed a robotic telescope which can be
controlled using a WWW browser .
Many conference organisers are making their conference proceedings
available on WWW. The conference papers for the Mosaic and the Web
conference held in Chicago in October 1994 were available on WWW at
the start of the conference 
Collaborative systems are being developed on WWW. WIT (WWW
Interactive Talk) is one example of a collaborative system which resembles
Usenet, but provides a mechanism for voting on a topic.
WWW And Open Systems
It is likely that not only will we see increasing uptake of existing types of
services on WWW, but also the development of new types of services.
The development of WWW is helped by the open nature of WWW:
- Clients available on multiple platforms.
- Servers available on multiple platforms.
- Public domain clients and servers available.
- Specifications (HTML, HTTP) freely available.
- Specifications not controlled by single company/organisation.
- Involvement in specification developments open to anyone.
 Information about CERN research activities is available at the URL
 The University of Leeds library catalogue is available at the URL
 The University of Bradford CWIS is available at the URL
 The Frog Dissection Kit is available at the URL
 The Fine Art service is available at the URL
 Information about the Chemical MIME type is available at the URL
 The Robotic Telescope is available at the URL
 The Mosaic and the Web conference proceeding are available at the URL
 WIT is available at the URL