Semantic Web

The Semantic Web is a vision of the future of the World Wide Web proposed by Tim Berners-Lee consisting of documents that are put together in such a way that it facilitates automated information gathering and research in a far more meaningful way than can be accomplished with current web search tools.

The usability and usefulness of the Web and its interconnected resources will be enhanced through:

documents 'marked up' with semantic information (an extension of the <meta> tags used in today's Web pages to supply information for Web search engines using web crawlers). This could be machine-readable information about the human-readable content of the document (such as the creator, title, description, etc of the document) or it could be purely metadata representing a set of facts (such as resources and services elsewhere in the site).
common metadata vocabularies (ontologies) and maps between vocabularies that allow document creators to know how to mark up their documents so that agents can use the information in the supplied metadata (so that Author in the sense of 'the Author of the page' won't be confused with Author in the sense of a book that is the subject of a book review).
automated agents to perform tasks for users of the Semantic Web using this metadata
web-based services (often with agents of their own) to supply information specifically to agents (for example, a Trust service that an agent could ask if some online store has a history of poor service or spamming).

The primary facilitators of this technology are: XML The core standard. Namespaces which resolve tag-name clashes within XML documents, DOM The Document Object Model which provides a set of standard interfaces for accessing XML and HTML document components. XPath Xlink XPointer RDF XSL XSLT Extensible Stylesheet Language SVG SMIL SOAP DTD XInclude XML fragment XML query language XHTML and the concept of metadata.

However, the business model of the Semantic Web is up in the air. Many web sites gain most of their revenue by selling advertisement space. Such advertisements are useless to an automated agent and may not be presented to the end user.