For those that work with RDF or similar you may be interested in these:
Raptor is a free software / Open Source C library that provides a set of parsers and serializers that generate Resource Description Framework (RDF) triples by parsing syntaxes or serialize the triples into a syntax. The supported parsing syntaxes are RDF/XML, N-Triples, Turtle, RSS tag soup including Atom 1.0 and 0.3, GRDDL for XHTML and XML. The serializing syntaxes are RDF/XML (regular, and abbreviated), N-Triples, RSS 1.0, Atom 1.0 and Adobe XMP.
Getting RDF data on the web can be hard to convince people to do, or to do correctly (see RSS). This service helps convert formats as need be and lets you access embedded RDF via GRDDL (such as microformats when they have a transformation) without the need to pre-process it yourself.
Triplr is built on Raptor and lets you convert formats between each other through a simple GET interface including JSON and RDF output from RSS, etc.