RDF as a model for metadata and RDF/XML as a way of serializing the
model are interesting, but the power of the specifications lies in
our ability to access the data easily, using techniques
we're familiar with from other data models, such as
the relational data model discussed in Chapter 6.
It is only natural that techniques used for one data model should be
adapted for use with another; so the method for accessing the
relational data model, Structured Query Language (SQL), is used in a
similar manner with RDF/XML through language techniques such as
SquishQL, RDQL, RQL, and others.
Many of the query languages and schemas mentioned in this chapter are
also covered in an online document
In addition, if your interest is more inclined to RDF as data (or to
the more logical side of RDF), check out the
www-rdf-rules discussion list at http://lists.w3.org/Archives/Public/www-rdf-rules/.