Growing triples on trees: An XML-RDF hybrid model for annotated documents

Considerable energy is spent towards enriching XML data on the web with semantics through annotations. These annotations can range from simple metadata to complex semantic relationships between data items. Although the vision of supporting such annotations is spreading, it still lacks the infrastructure that will enable it. To this end we propose a framework enabling the storage and querying of annotated documents. We introduce (i) the XR data model, in which annotated documents are XML documents described by RDF triples and (ii) the query language XRQ to interrogate annotated documents through their structure and their semantics. The prototype platform XRP for the management of annotated documents has been developed, to show the relevance of our approach through experiments.