3kbo is dedicated to building semantic web applications.
Wikipeida defines the semantic web as “an evolving extension of the World Wide Web in which web content can be expressed not only in natural language, but also in a form that can be read and used by software agents, thus permitting them to find, share and integrate information more easily”.
The W3C defines the specifications which form the basis of the Semantic Web. These are maintained by the W3C Semantic Web Activity . In its words the “The Semantic Web provides a common framework that allows data to be shared and reused across application, enterprise, and community boundaries.”
Key specifications are Resource Description Framework (RDF) which is used to represent information and to exchange knowledge in the Web and OWL (Web Ontology language) which is used to publish and share sets of terms called ontologies, supporting advanced Web search, software agents and knowledge management.
Other important standards are SPARQL, GRDDL and SWRL.
SPARQL query language for RDF can be used to express queries across diverse data sources, whether the data is stored natively as RDF or viewed as RDF via middleware. SPARQL contains capabilities for querying required and optional graph patterns along with their conjunctions and disjunctions. SPARQL also supports extensible value testing and constraining queries by source RDF graph. The results of SPARQL queries can be results sets or RDF graphs.
GRDDL is a mechanism for Gleaning Resource Descriptions from Dialects of Languages. The GRDDL specification introduces markup for declaring that an XML document includes gleanable data and for linking to an algorithm, typically represented in XSLT, for gleaning the resource descriptions from the document.