Aperture http://aperture.sourceforge.net/ is an open source java framework that can crawl file systems (including shared network drives and removeable media), websites and IMAP mail boxes to extract information into RDF.

Aperture is built on top RDF2Go http://rdf2go.semweb4j.org/ allowing Aperture to work easily with popular RDFStores like Sesame and Jena.

Aperture example applications can crawl Flickr, Delicious, filesystems, calendars, mailboxes and web sites.