SWOOGLE
Swoogle extracts metadata for each discovered document, and computes relations among them. Discovered documents are also indexed by an information retrieval system which can use either character N-Gram or URIrefs as keywords to find relevant documents and to compute the similarity among a set of documents. One of the interesting properties we compute is ontology rank, a measure of the importance of a Semantic Web document.
http://swoogle.umbc.edu/
