This report surveys the state of semantic web storage for RDF / triple data using existing free software tools. It takes a practical approach by targeting the work to the needs of developers, answering frequently asked questions related to this subject. The report first reviews previous work in surveying semantic web data, schema and triple stores, then gives an overview of the major systems with their feature set and maturity and then uses that information to provide a set of FAQs with answers related to storing semantic web data.
3store is an RDF "triple store", written in C and backed by MySQL and Berkeley DB. It is an optimisation and port of an older triple store (WebKBC). It provides access to the RDF data via RDQL or SPARQL over HTTP, on the command line or via a C API.
YARS is a data store for RDF in Java and allows for querying RDF based on a declarative query language, which offers a somewhat higher abstraction layer than the APIs of RDF toolkits such as Jena or Redland.