The Semantic Web is a set of technologies for presenting structured information on the web. The basic idea is that if the sorts of web pages you see nowadays are like text files, then the semantic web (or Semantic Web) is like an interconnected set of relational databases.

There are more grandiose ways of expressing this, which are worth reading.

The technologies that enable the semantic web are being specified and standardized by the World Wide Web Consortium. The primary technology is RDF, which is a model for representing structured data. There are six main specifications:

• RDF Primer
• RDF/XML Syntax Specification
• RDF Vocabulary Description Language: RDF Schema
• RDF Concepts and Abstract Syntax
• RDF Semantics
• RDF Test Cases

Any structured data model worth its salt has a nice expressive way of defining its ontology. RDF Schema is built into RDF, but there's an important application/extension of RDF called OWL (for Web Ontology Language) which is more expressive than RDF Schema. OWL has its own set of six specifications:

• OWL Overview
• OWL Guide
• OWL Reference
• OWL Semantics and Abstract Syntax
• OWL Test Cases
• OWL Use Cases and Requirements

-- David Goss-Grubbs - 28 Oct 2004