RDF in Canonical XML (RDF/cXML)

Ossi Nykänen, 24 February 2011

In many concrete Resource Description Framework (RDF) data processing applications, it is good to have the possibility of interpreting RDF/XML data either as in RDF or as in XML. We call this the dual interpretation of RDF/XML. For this purpose, we have defined a canonical form of RDF/XML called RDF in Canonical XML (RDF/cXML).

RDF/cXML can be written in several forms: As (plain) RDF/cXML, in the Description Normal Form, in the In-Scope URI Free Normal Form, and/or in the Relative URI-Free Normal Form. Intuitively, the normal forms reflect the complexity of parsing according to the XML interpretation.

Note: This work originally started during the OPAALS project (2006-2010), but has been since applied and continued, e.g., in the SemoGen project (2010-2012).


CanRDF implements a RDF/cXML transducer. It reads an RDF/XML file and outputs it in the RDF/cXML canonical, description and relative URI free normal forms. This makes is possible to, e.g., process RDF data reliably using XQuery, XSLT, and DOM. The canonical form itself is in RDF/XML, but using a restricted subset of the syntax. The restricted syntax is able to capture all aspects of the RDF data model.


Requires a Java VM version 1.4 or later.


Please consult the following help screen:

CanRDF: A data processor for converting RDF/XML into canonical RDF/cXML.

Output is in the following normal forms: Description, Relative URI Free.

Usage: [java -jar canrdf.jar] source [dest]

Notes: Processing will overwrite the dest file (if given)!
Source may be read over the Internet but dest must be a local file.

Example: [java -jar canrdf.jar] example.rdf out_rdfc.xml

The implementation is based on Jena 2.6.4; see http://jena.sourceforge.net/ .

RDF/cXML Schema

The file rdfcxml-sch.xml provides an informative RDF/cXML schema in relative URI free normal form. The schema is written with ISO Schematron.

-- OssiNykanen - 24 Feb 2011
Topic attachments
I Attachment Action Size Date Who Comment
canrdf.jarjar canrdf.jar manage 10741.7 K 24 Feb 2011 - 09:50 OssiNykanen  
rdfcxml-sch.xmlxml rdfcxml-sch.xml manage 5.1 K 24 Feb 2011 - 09:51 OssiNykanen  
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Topic revision: r11 - 13 Dec 2011 - 13:50:36 - JaakkoSalonen


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