by Keith G. Jeffery
It is impossible to imagine modern life without the Web. Tim Berners-Lee's original vision, so simple and elegant, has become part of the fabric of our lives. It is hard to realize that in less than two decades a line-mode 'techie' tool from a research laboratory has become indispensable to all for information, communication, business and research.Within the first few years of the Web, teams worked on aspects such as Web-database integration - leading to an explosion of e-business, especially B2C (Business to Customer) - and stylesheets to assist in consistent presentation. As time progressed and the Web became increasingly widespread, accessibility issues were addressed. Graphics recommendations such as PNG and SVG were developed. Synchronized multimedia (SMIL) was developed. Teams were already working on trust and security and on metadata to describe Web pages when 'Weaving the Web' was published, emphasising the Web of trust and semantic Web. The development of Java allowed the production of applets and servlets, leading to the client-server model being replaced by a new three-level architecture. Web services with XML provided data transfer and workflow capabilities for business. Web access from mobile devices became possible and the Mobile Web Initiative was launched by W3C, which has been in existence since the early years, providing a forum for consulting members and pushing through recommendations as effective standards.
Web of Trust
With some background in PICS (Platform for Internet Content Selection) various researchers have been developing systems for trust and security in a Web environment. The definition of standard document formats (using XML) to exchange information about companies, products and services, and the provision of SLAs (service level agreements), has underpinned the trust effort. Cryptography with page-content encoding/decoding has been a major part of security. Privacy has also been addressed, from techniques for authenticating users to methods of authorizing (and therefore also restricting) access.
The development of the Resource Description Framework (RDF), essentially a binary relational representation, allowed more expressiveness to be encoded in Web applications. DAML and OIL - early ontology languages - led to the recommendation OWL for constructing domain ontologies to be used in assisting interoperation (or for input validation, query improvement and answer explanation). There is still a long way to go, but semantics are gradually being managed in the Web environment.
The increasing capacity of handheld devices and networks has led to demand for access to the Web on mobile devices. The possibilities include data input from attached detectors (eg video), full-quality video and sound output, and push technology to make the device intelligent with respect to the user's objectives and the current spatio-temporal environment.
The potential of the Web as a platform for interaction and cooperation is now emerging with the so-called Web 2.0 ideas. These include not only the use of services but also participation by users individually or collectively (collective intelligence). This can occur, for example, through blogs and Wikis with tagging, faster page loads and interactions using AJAX technology, access to multiple information sources and their integration through 'mashups', peer-to-peer connectivity and increasingly intelligent push technology.
The development of Web services provided a sort of application programming interface (API) to allow programming of the Web, rather than simply authoring or generating content and then making it available. With XML encoding of the information, cooperative working including workflow is made possible. It also made it possible to consider SOA (service-oriented architecture), which leads to shorter development times for applications and easier maintenance. However this also entailed metadata descriptions of services and business processes to allow discovery and use. There has been an explosion of metadata offerings in this domain - many application-domain specific and some standardisation is needed.
Starting as metacomputing (linked supercomputers) in North America in the mid- to late nineties, the Europeans proposed that GRID services be based on Web services so that GRIDs could become a ubiquitous facility. In this vein, work by the Next Generation Grid Expert Group of the European Commission has led to much R&D activity in services and their specification with metadata.
The future of the Web lies first with the convergence of the semantic Web, Web of trust and Web 2.0, followed by twinning with GRIDs. This combined e-infrastructure will allow more or less unlimited access to information, business processing, entertainment, education, research and so forth.
The outstanding barriers to realizing this vision concern the development and acceptance of standards. This is partly because some standards (recommendations in W3C terms) are inadequate, and partly because there are competing commercial interest groups. However, to provide ubiquitous interoperability these standards must be developed, accepted and evolved in a structured way.
As they were ten years ago, the key standards required now are in the areas of semantics (particularly of metadata to allow management of services and management of information resources) and trust/security (another metadata-controlled area). Resolution of these areas will allow confident progression to the vision. ERCIM researchers are involved in projects addressing these very issues and are working together with the W3C Europe, located within ERCIM.
Keith G. Jeffery, ERCIM President
Science and Technology Facilities Council, UK