Anything to Triples : Anything To Triples (any23) is a library, a web service and a command line tool that extracts structured data in RDF format from a variety of Web docu...
Hoppscotch : A free, online, open source API request builder
DERI Pipes : Inspired by Yahoo's Pipes, DERI Pipes is an engine and graphical environment for general Web Data transformations and Mashup.
Linked Data : This site exists to provide a home for, or pointers to, resources from across the Linked Data community.
Freebase : A community-curated database of well-known people, places, and things
Calais is a rapidly growing toolkit of capabilities that allow you to readily incorporate state-of-the-art semantic functionality within your blog, content management system, website or application.