SIOC/OpenLink Data Spaces/Sparql Endpoint

From W3C Wiki

ODS SPARQL endpoints provide access to SIOC instance data from a range of ODS-Application instances

that include: Weblogs, Wikis, Aggregated Feeds (RSS 1.0/2.0 and Atom), Shared Bookmarks, Discussions (comment threads), Photo Galleries, Briefcase (WebDAV File Server) etc.

The Live ODS Demo Server and MyOpenLink.net (Alpha) Service are examples of ODS instances that expose SIOC instance data to SPARQL Query Service clients.