D2R Server is a tool for publishing the content of relational databases on the Semantic Web, a global information space consisting of linked data.
Data on the Semantic Web is modelled and represented in RDF. D2R Server uses a customizable D2RQ mapping to map database content into this format, and allows the RDF data to be browsed and searched - the two main access paradigms to the Semantic Web.
D2R Server's Linked Data interface makes RDF descriptions of individual resources available over the HTTP protocol. An RDF description can be retrieved simply by accessing the resource's URI over the Web. Using a Semantic Web browser like Tabulator (slides) or Disco, you can follow links from one resource to the next, surfing the Web of Data.
The SPARQL interface enables applications to search and query the database using the SPARQL query language over the SPARQL protocol.
A traditional HTML interface offers access to the familiar Web browsers.
Requests from the Web are rewritten into SQL queries via the mapping. This on-the-fly translation allows publishing of RDF from large live databases and eliminates the need for replicating the data into a dedicated RDF triple store.
Read more about the interfaces offered by D2R Server, including example HTTP requests and responses, in the Technical Note Publishing Databases on the Semantic Web.
