1. RDF(S) Tools Adrian Pop, adrpo@ida.liu.se Programming Environments Laboratory Linköping University

2. November 03, 2003 2  Introduction  Tool categories  parsers, validators  editors, query tools  databases, crawlers  Editors demos  RDFAuthor, IsaViz, RDFedt, InferEd  Query Tools  Jena RDQL demo  Conclusions

3. November 03, 2003 3  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)

4. November 03, 2003 4  Parsers (Jena, Redland, SWI-Prolog parser)  Validators (W3C RDF Validation service)  Editors (IsaViz, RDFAuthor, RDFEd, InferEd)  Query tools (Jena, etc)  Databases (RSSDB, RDFLib)

5. November 03, 2003 5  Jena - A semantic Web Framework for Java  http://jena.sourceforge.net/ 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

6. November 03, 2003 6  Redland RDF Application Framework  http://www.redland.opensource.ac.uk/ 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

7. November 03, 2003 7  SWI-Prolog parser (Online Demo)  http://gollem.swi.psy.uva.nl/cgi-bin/pl- cvsweb/pl/packages/sgml/RDF/online.html?rev=1.11 http://gollem.swi.psy.uva.nl/cgi-bin/pl- cvsweb/pl/packages/sgml/RDF/online.html?rev=1.11  RDFS explorer, RDF Semantic Extensions  http://wonkituck.wi-inf.uni-essen.de/rdfs.html http://wonkituck.wi-inf.uni-essen.de/rdfs.html  Interesting feature:  provide semantics in Prolog for your properties path(S,O) :- statement(S,path,O). path(X,Z) :- statement(X,path,Y), path(Y,Z).

8. November 03, 2003 8  RDF Validation Service  http://www.w3.org/RDF/Validator/ http://www.w3.org/RDF/Validator/  Validating RDF Parser  http://139.91.183.30:9090/RDF/index.html http://139.91.183.30:9090/RDF/index.html  In general all the RDF parsers do some kind of validation

9. November 03, 2003 9  RDFAuthor  http://rdfweb.org/people/damian/2001/10/RDFAuthor/ http://rdfweb.org/people/damian/2001/10/RDFAuthor/ RDFAuthor Demo

10. November 03, 2003 10  IsaViz  http://www.w3.org/2001/11/IsaViz/ http://www.w3.org/2001/11/IsaViz/ IsaViz Demo

11. November 03, 2003 11  RDFedt  http://www.jan-winkler.de/dev/e_rdfe.htm http://www.jan-winkler.de/dev/e_rdfe.htm RDFedt demo

12. November 03, 2003 12  InferEd  http://www.intellidimension.com/pages/site/ products/infered/ http://www.intellidimension.com/pages/site/ products/infered/ InferEd Demo

13. November 03, 2003 13  Jena RDQL examples  Queries over the foaf.rdf filefoaf.rdf  Query 1, Select all SELECT * WHERE(?x ?y ?z)  Query 1, Select persons that knows me SELECT ?person, ?knows WHERE(?x ?z), (?x ?person), (?z ?knows)  Go Go

14. November 03, 2003 14 Storage of RDF graphs  Files  xml format,.n3 format, N-triples format  Databases  relational databases (MySQL, PostgreSQL)  Object-Oriented Databases (ZODB)

15. November 03, 2003 15  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)

16. November 03, 2003 16 Thank you! Questions?

17. November 03, 2003 17 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