RDF(S) Tools
Adrian Pop, adrpo@ida.liu.se
Programming Environments Laboratory
Linköping University
<Outline/>
 Introduction
 Tool categories
 parsers, validators
 editors, query tools
 databases, crawlers
 Editors demos
 RDFAuthor, IsaViz, RDFedt, InferEd
 Query Tools
 Jena RDQL demo
 Conclusions
November 03, 2003
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<Introduction/>
 Resource Description Framework (RDF)
 standard for describing resources on the web
 RDF Schema (RDFS)
 RDF Vocabulary Description Language
 RDF(S) Tools must
 read RDF data (parsers/validators)
 store RDF data (XML format, triples, or
relational/OO DBs)
 use RDF data (applications, RSS news, etc)
 manipulate RDF data (inference, query, etc)
November 03, 2003
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<Categories/>
 Parsers (Jena, Redland, SWI-Prolog parser)
 Validators (W3C RDF Validation service)
 Editors (IsaViz, RDFAuthor, RDFEd, InferEd)
 Query tools (Jena, etc)
 Databases (RSSDB, RDFLib)
November 03, 2003
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<Parsers part=“1”/>
 Jena - A semantic Web Framework for Java
 http://jena.sourceforge.net/
 A RDF API
 Reading and writing RDF in RDF/XML, N3 and
N-Triples
 An OWL API
 In-memory and persistent storage
 RDQL – a query language for RDF
 Later on, a RDQL demo
November 03, 2003
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<Parsers part=“2”/>
 Redland RDF Application Framework
 http://www.redland.opensource.ac.uk/
 A modular, object based library written in C
 Java, Perl, PHP, Python, Ruby and Tcl interfaces for
manipulating the RDF graph and parts
 Parsers and Serializers for reading and writing RDF
 Storage for graphs in memory and on disk
 Query APIs for the graph by Statement (triples) or by
Nodes and Arcs
 Statement Streams for construction, parsing,
de/serialisation of graphs
 Start of query language support.
 No memory leaks so far
November 03, 2003
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<Parsers part=“3”/>
 SWI-Prolog parser (Online Demo)
 http://gollem.swi.psy.uva.nl/cgi-bin/plcvsweb/pl/packages/sgml/RDF/online.html?rev=1.11
 RDFS explorer, RDF Semantic Extensions
 http://wonkituck.wi-inf.uni-essen.de/rdfs.html
 Interesting feature:
 provide semantics in Prolog for your properties
<rdf:Property rdf:ID="path">
<rdfs:isDefinedAs rdf:parseType="Literal">
path(S,O) :- statement(S,path,O).
path(X,Z) :- statement(X,path,Y), path(Y,Z).
</rdfs:isDefinedAs>
</rdf:Property>
November 03, 2003
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<Validators/>
 RDF Validation Service
 http://www.w3.org/RDF/Validator/
 Validating RDF Parser
 http://139.91.183.30:9090/RDF/index.html
 In general all the RDF parsers do some kind
of validation
November 03, 2003
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<Editors part=“1” demo=“yes”/>
 RDFAuthor
 http://rdfweb.org/people/damian/2001/10/RDFAuthor/
RDFAuthor Demo
November 03, 2003
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<Editors part=“2” demo=“yes”/>
 IsaViz
 http://www.w3.org/2001/11/IsaViz/
IsaViz Demo
November 03, 2003
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<Editors part=“3” demo=“yes”/>
 RDFedt
 http://www.jan-winkler.de/dev/e_rdfe.htm
RDFedt demo
November 03, 2003
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<Editors part=“4” demo=“yes”/>
 InferEd
 http://www.intellidimension.com/pages/site/
products/infered/
InferEd Demo
November 03, 2003
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<Query demo=“yes”/>
 Jena RDQL examples
 Queries over the foaf.rdf file
 Query 1, Select all
SELECT *
WHERE(?x ?y ?z)
 Query 1, Select persons that knows me
SELECT ?person, ?knows
WHERE(?x <http://xmlns.com/foaf/0.1/knows> ?z),
(?x <http://xmlns.com/foaf/0.1/name> ?person),
(?z <http://xmlns.com/foaf/0.1/name> ?knows)
 Go
November 03, 2003
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<Databases/>
Storage of RDF graphs
 Files
 xml format, .n3 format, N-triples format
 Databases
 relational databases (MySQL, PostgreSQL)
 Object-Oriented Databases (ZODB)
November 03, 2003
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<Conclusions/>
 RDF Tools
 are mature enough
 become more complex
 RDF is more widely used
 RSS feeds
 Mozilla sidebar, Bookmarks, etc
 RDFGateway (application + web + RDF
deductive DB)
November 03, 2003
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<End/>
Thank you!
Questions?
November 03, 2003
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Resources
Ontology Storage and Querying
http://139.91.183.30:9090/RDF/publications/tr308.pdf
RDF Schema explorer + RDF Semantic Extensions
http://wonkituck.wi-inf.uni-essen.de/rdfs.html
Dave Beckett's Resource Description Framework (RDF) Resource Guide
http://www.ilrt.bris.ac.uk/discovery/rdf/resources/
RDFAuthor, RDFAuthor Tutorial
http://rdfweb.org/people/damian/2001/10/RDFAuthor/
http://rdfweb.org/people/damian/2001/10/RDFAuthor/Tutorial/
Jena - A semantic Web Framework for Java
http://jena.sourceforge.net/
Redland RDF Application Framework
http://www.redland.opensource.ac.uk/
RDF Validation Service
http://www.w3.org/RDF/Validator/
Validating Parser (VRP), RDF Schema Specific Database (RSSDB), The RDF Query Language (RQL)
http://139.91.183.30:9090/RDF/index.html
RDFedt
http://www.jan-winkler.de/dev/e_rdfe.htm
November 03, 2003
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