Portals

• W3C Semantic Web Activity
• The Sematic Web Community wiki

Standards and Recommendations

• Resource Description Framework (RDF): Concepts and Abstract Syntax (W3C Recommendation 10 February 2004)
• RDF/XML Syntax Specification (W3C Recommendation 10 February 2004)
• SKOS Simple Knowledge Organization System Reference (W3C Candidate Recommendation 17 March 2009)

Tools

• Protégé ontology editor
• Pellet OWD-DL reasoner