Qure is an RDF store written in C using Tokyo Cabinet. It can be used as a stand-alone library, or as a store for Redland.
Qure is still in the experimental stage (in particular, use by multiple processes at once is not safe). Preliminary experiments show it to be significantly faster than other Redland stores, and competitive with in-memory data structures despite being persistent (when the data size is small enough for such a comparison to be possible).
Download
Qure is not yet released and only exists in SVN:
svn co http://svn.drobilla.net/qure/trunk qure