This service hosts (almost) all Dutch national regulations in CEN MetaLex XML and as RDF Linked Data. Current coverage is 45,165 document versions, covering practically all regulations available through

Regulations are converted on a daily basis, through a generic conversion script, that is able to perform a similar conversion for any 'legislative' XML based on a standard mapping from legacy XML elements to CEN MetaLex. See the script's GitHub page for installation and usage instructions.

This dataset was developed by Rinke Hoekstra and is hosted by the Leibniz Center for Law of the Universiteit van Amsterdam.

Contrary to the portal, the MetaLex server maintains all versions of regulations at a highly granular level. We provide an extensive example below, but the impatient can go directly to a version of the "Regeling beleidsregels vereveningsbijdrage zorgverzekering 2006" (See here for the document on

When using this server in your own work, please cite the following publication:

Rinke Hoekstra. The MetaLex Document Server - Legal Documents as Versioned Linked Data (2011), Proceedings of the International Semantic Web Conference (ISWC) 2011.


CEN MetaLex is a standard for how sources of law and references to sources of law are to be represented in XML. It is an interchange format, a lowest common denominator for other standards, intended not to replace jurisdiction-specific standards and vendor-specific formats in the publications process but to impose a standardized view on legal documents for the purposes of information exchange and interoperability in the context of software development.
Linked Data is a W3C sanctioned approach to publishing metadata on the Web using a set of standard languages and metadata vocabularies.


The following links are several example URIs for the "Regeling beleidsregels vereveningsbijdrage zorgverzekering 2006" (See here for the document on Clicking on any of them, will redirect to a Pubby browser of the RDF metadata about the regulation.

Alternatively, you can access the document directly, by using a 'manifestation' (or 'document') URI that identifies the document (or part of it) in one of the available formats:

You can try out content negotiation with tools such as 'wget' or 'curl' to retrieve non-HTML content from the 'expression' and 'work' level URIs.



Resources available on this server are disclosed by means of Cool URIs.

That is, depending on the accept header sent by the client that performs an HTTP request to the URI of a resource, the server performs a 2-step redirect (actually 3, in this case) to the manifestation that is interpretable by the client. A manifestation is essentially a version of (part of) a document (an expression) in a certain format.

This server is able to handle the following content types:

  • HTML: application/xml, application/xhtml+xml, text/html
  • RDF/XML: application/rdf+xml
  • Turtle: text/rdf+n3, application/x-turtle
  • XML: text/xml
  • Net: text/plain

URI resolution works as follows:

  • A request for an expression URI (i.e. one that starts with '' ) is redirected by means of an HTTP 303 to a document URI (one that starts with '')
  • This leads to a request for the document URI.
  • We then parse the HTTP accept header of the request, and redirect (via HTTP 302) to the URI of the manifestation URI (i.e. a URI ending with data.rdf, data.n3, data.ttl, data.html, data.xml or
  • For XML and NET files, we then redirect (via HTTP 302) to the URL of the actual file that contains the description of the resource.
  • For RDF, Turtle and N3 we directly return the the result of a SPARQL DESCRIBE query for the expression URI.
  • For HTML, we redirect (via HTTP 302) to a Marbles server that renders an HTML representation of the result of a SPARQL DESCRIBE query for the expression URI. (Marbles actually sends a request to the expression URI with an accept header that makes this server redirect to the RDF description)



Metadata follows the guidelines of the CEN MetaLex standard. Legislative events are represented both by means of the MetaLex ontology, as well as using the W3C Provenance Vocabulary (PROV), the Simple Event Model (SEM) and the W3C Time Ontology.

SPARQL Endpoint

RDF representations of regulations reside in an OpenLink Virtuoso Open Source Edition triple store. Feel free to use the YASGUI query interface, developed by Laurens Rietveld and COMMIT/Data2Semantics.

MetaLex XML documents currently reside on the filesystem of the server.

Copyright (c) 2011-2014 - Rinke Hoekstra, Leibniz Center for Law, Universiteit van Amsterdam and VU University Amsterdam