WordNet - a lexical database for the English language
Given my interest in glossaries and concept dictionaries, I am intrigued by WordNet from the Princeton Cognitive Science Laboratory, which bills itself as "a lexical database for the English language." The web site says:
WordNet(R) 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. Synsets are interlinked by means of conceptual-semantic and lexical relations. The resulting network of meaningfully related words and concepts can be navigated with the browser. WordNet is also freely and publicly available for download. WordNet's structure makes it a useful tool for computational linguistics and natural language processing.
I have not dug into this enough to get a handle on whether or how they utilize RDF, but the effort does certainly seem quite interesting.