UI / components (Flex and Share/Surf/Ajax):

auto-tagging, semantic search, multiple semantic tag clouds.

Alfresco Server extensions (REST api to Java semantic services):

auto-tagging, RDF, SPARQL, OWL, Calais/UIMA/GATE auto generation of metadata.

Alfresco WCM support for semantic web sites

For now see FlexSpaces for Flex components, and Calais Integration for Alfresco for auto-tagging, auto generation of metadata:

FlexSpaces showing Alfresco + Calais Integration and AIR drag drop features