WordNet is a large lexical database of English, developed under the direction of George A. Miller. Nouns, verbs, adjectives and adverbs are grouped into sets of cognitive synonyms (synsets), each expressing a distinct concept.
This is the the Annozilla project, designed to view and create annotations associated with a web page, as defined by the W3C Annotea project. The idea is to store annotations as RDF on a server, using XPointer to identify the region of the document being annotated.
E. Oren, J. Breslin, and S. Decker. WWW '06: Proceedings of the 15th international conference on World Wide Web, page 1071--1072. New York, NY, USA, ACM Press, (2006)