RDF(S) Tools

1
RDF(S) Tools
Adrian Pop, adrpo_at_ida.liu.se Programming
Environments Laboratory Linköping University
2
ltOutline/gt

• Introduction
• Tool categories
• parsers, validators
• editors, query tools
• databases, crawlers
• Editors demos
• RDFAuthor, IsaViz, RDFedt, InferEd
• Query Tools
• Jena RDQL demo
• Conclusions

3
ltIntroduction/gt

• 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
ltCategories/gt

• Parsers (Jena, Redland, SWI-Prolog parser)
• Validators (W3C RDF Validation service)
• Editors (IsaViz, RDFAuthor, RDFEd, InferEd)
• Query tools (Jena, etc)
• Databases (RSSDB, RDFLib)

5
ltParsers part1/gt

• 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

6
ltParsers part2/gt

• 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

7
ltParsers part3/gt

• SWI-Prolog parser (Online Demo)
• http//gollem.swi.psy.uva.nl/cgi-bin/pl-cvsweb/pl/
  packages/sgml/RDF/online.html?rev1.11
• RDFS explorer, RDF Semantic Extensions
• http//wonkituck.wi-inf.uni-essen.de/rdfs.html
• Interesting feature
• provide semantics in Prolog for your properties
• ltrdfProperty rdfID"path"gt
• ltrdfsisDefinedAs rdfparseType"Literal"gt
• path(S,O) - statement(S,path,O).
• path(X,Z) - statement(X,path,Y),
  path(Y,Z).
• lt/rdfsisDefinedAsgt
• lt/rdfPropertygt

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ltValidators/gt

• RDF Validation Service
• http//www.w3.org/RDF/Validator/
• Validating RDF Parser
• http//139.91.183.309090/RDF/index.html
• In general all the RDF parsers do some kind of
  validation

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ltEditors part1 demoyes/gt

• RDFAuthor
• http//rdfweb.org/people/damian/2001/10/RDFAuthor/
  
• RDFAuthor Demo

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ltEditors part2 demoyes/gt

• IsaViz
• http//www.w3.org/2001/11/IsaViz/
• IsaViz Demo

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ltEditors part3 demoyes/gt

• RDFedt
• http//www.jan-winkler.de/dev/e_rdfe.htm
• RDFedt demo

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ltEditors part4 demoyes/gt

• InferEd
• http//www.intellidimension.com/pages/site/product
  s/infered/
• InferEd Demo

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ltQuery demoyes/gt

• 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 lthttp//xmlns.com/foaf/0.1/knowsgt ?z),
• (?x lthttp//xmlns.com/foaf/0.1/namegt
  ?person),
• (?z lthttp//xmlns.com/foaf/0.1/namegt ?knows)
• Go

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ltDatabases/gt

• Storage of RDF graphs
• Files
• xml format, .n3 format, N-triples format
• Databases
• relational databases (MySQL, PostgreSQL)
• Object-Oriented Databases (ZODB)

15
ltConclusions/gt

• 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)

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ltEnd/gt

• Thank you!
• Questions?

17
Resources

• Ontology Storage and Querying
• http//139.91.183.309090/RDF/publications/tr308.p
  df
• 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//139.91.183.309090/RDF/index.html
• RDFedt
• http//www.jan-winkler.de/dev/e_rdfe.htm