An Overview of W3C Semantic Web Activity:

The Semantic Web is an extension of the current Web in which the meaning of information is clearly and explicitly linked from the information itself. The World Wide Web Consortium (W3C) Semantic Web Activity, researchers and industrial partners want to enable standards and technologies to allow data on the Web to be defined and linked in such a way that it can be used for more effective discovery, automation, integration and reuse across various applications. The Internet will reach its full potential when data can be processed and shared by automated tools as well as by people.

The Semantic Web fosters greater data reuse by making it available for purposes not planned or conceived by the data provider. E.g. you want to locate news articles published in the previous month about companies headquartered in cities with populations under 500,000. The information may be there in the Web, but currently only in a form that requires intensive human processing.

The Semantic Web will allow:

- It will allow information to surface in the form of data, so that a program doesn't have to strip the formatting, pictures and ads off a Web page and guess at how the remaining page markup denotes the relevant bits of information.

- It will allow people to generate files that explain – to a machine – the relationship between different sets of data. For example, one will be able to make a "semantic link" between a database with a "zipcode" column and a form with a "zip" field to tell the machines that they do actually mean the same thing. This will allow machines to follow links and facilitate the integration of data from many different sources.

Being "semantically linked" means that the Semantic Web will allow people to make relations with the data. Relationships such as hasLocation, worksFor, isAuthorOf, hasSubjectOf, dependsOn, etc., will allow web machines to find related information in a more natural way. At the moment these kind of relationships are there but only they can be understood by people.

The development of the Semantic Web is underway in at least two very important areas: (1) from the infrastructural and architectural position defined by W3C and (2) in a more directed application-specific fashion by those leveraging Semantic Web technologies in various demonstrations, applications and products.


Enabling standards:
Uniform Resource Identifiers (URIs) are fundamental for the current Web and are in turn a foundation for the Semantic Web. URIs provide the ability for uniquely identifying resources of all types – not just Web documents – as well as relationships among resources. Besides the development of the Extensible Markup Language (XML) and the Resource Description Framework (RDF) help to represent relationships and to obtain meaning.

The W3C Semantic Web Activity plays a leadership role in both the design of specifications and the open, collaborative development of technologies focused on representing relationships and meaning and the automation, integration and reuse of data.

The base level standards for supporting the Semantic Web are currently being refined by the RDF Core Working Group. 

The Web Ontology (http://www.w3.org/2001/sw/WebOnt/) Working Group standards efforts are designed to build upon the RDF core work a language, OWL ( http://www.w3.org/TR/owl-ref/), for defining structured, Web-based ontologies. Ontologies can be used by automated tools to power advanced services such as more accurate Web search, intelligent software agents and knowledge management. Web portals, corporate website management, intelligent agents and ubiquitous computing are just some of the identified scenarios that helped shape the requirements for this work.

Semantic Web Advanced Development (SWAD):
SWAD-Europe aims to highlight practical examples of where real value can be added to the Web through Semantic Web technologies. Their focus is on providing practical demonstrations of how (1) the Semantic Web can address problems in areas such as sitemaps, news channel syndication, thesauri, classification, topic maps, calendaring, scheduling, collaboration, annotations, quality ratings, shared bookmarks, Dublin Core for simple resource discovery, Web service description and discovery, trust and rights management and (2) effectively and efficiently integrate them.

The W3C is running some other projects such as: SWAD-Simile and SWAD-Oxygen

Conclusion:

- The Semantic Web is an extension of the current Web.

- It is based on the idea of having data on the Web defined and linked such that it can be used for more effective discovery, automation, integration and reuse across various applications.

- Provides an infrastructure that enables not just Web pages, but databases, services, programs, sensors, personal devices and even household appliances to both consume and produce data on the Web.

- Software agents can use this information to search, filter and prepare information in new and exciting ways to assist Web users.

- New languages make significantly more of the information on the Web machine-readable.

Notes:

Both authors are part of the W3C and can be contacted by email Eric Miller em@w3.org and Ralph Swick swick@w3.org

References:

An Overview of W3C Semantic Web Activity: http://onlinelibrary.wiley.com/doi/10.1002/bult.280/full