GRDDL is a mechanism for Gleaning Resource Descriptions from Dialects of Languages. It is a technique for obtaining RDF data from XML documents and in particular XHTML pages. Authors may explicitly associate documents with transformation algorithms, typically represented in XSLT, using a link element in the head of the document. Alternatively, the information needed to obtain the transformation may be held in an associated metadata profile document or namespace document. Clients reading the document can follow links across the Web using techniques described in the GRDDL specification to discover the appropriate transformations. This document uses a number of examples from the GRDDL Use Cases document to illustrate, in detail, the techniques GRDDL provides for associating documents with appropriate instructions for extracting any embedded data. (from homepage)
Gleaning Resource Descriptions from Dialects of Languages