The Leibniz Center for Law of the University of Amsterdam has made all Dutch legislation available as CEN MetaLex and Linked Open Data through the MetaLex Document Server portal (MDS). “The XML source documents currently made available by the Dutch government are simply not good enough”, says Rinke Hoekstra, researcher at the Leibniz Center, and the Knowledge Representation group of the VU University Amsterdam.

The MetaLex Document Server improves over the XML API of the official portal by:

• Providing persistent, versioned identifiers of all elements of  regulations.
• Maintaining source XML for all versions of legislation since May 2011, rather than only the latest version.
• All metadata is published as RDF Linked Data, is linked to the original legislative sources, and uses standard vocabularies such as the MetaLex Ontology, Dublin Core, Open Provenance Model Vocabulary, Simple Event Model,FOAF, etc.
• All documents and metadata are available through ‘content negotiation’: content can be retrieved by using the URI (identifier) of an element as a URL.
• Metadata is accessible through a SPARQL endpoint
• Citations between regulations are made available in a format suitable for social network analysis (Pajek/Gephi)
• A generic conversion script for transforming any legislative XML to CEN MetaLex

For more information, have a look at the presentation on slideshare, or contact Rinke Hoekstra directly.

A report on this work will be published as part of the proceedings of the International Semantic Web Conference (ISWC) 2011: “Rinke Hoekstra. The MetaLex Document Server – Legal Documents as Versioned Linked Data”