What is the 'Semantic Web'?

Semantic Web is world wide web founder Tim Berners-Lee's idea for how to build a new machine readable Internet as an extension to the current text-based Internet.  Some of this data is is used to represent knowledge models ('Ontologies'), which are represented using a W3C recommendation named 'OWL'.  SemTalk reads and writes OWL files.  All knowledge which is available on the Semantic Web can be used for process models.