==== ARQ 2.2

ARQ 2.2 is a complete implementation of the SPARQL query language
including support for custom filter functions, property functions
and free text search.  It also provides an update language
based on SPARQL.

ARQ includes a number of advanced SPARQL features:

  * Free text search (provided by Lucene)
  * Property functions for defining calculated properties
  * Query inference graphs (Jena inference)
  * Framework for access to wrapped data sources (RDF and non-RDF) 
  * Client query engine for remote SPARQL services

ARQ includes a number of SPARQL extensions:

  * SPARQL/Update
  * GROUP BY/HAVING
  * Counting
  * Federated query : SERVICE - call-out to another query service 
  * Expressions in the SELECT clause 

== Links

Download:
  http://prdownloads.sourceforge.net/jena/ARQ-2.2.zip

Home page:
  http://jena.sourceforge.net/ARQ/

ARQ is also available via anonymous SVN:
  https://jena.svn.sourceforge.net/svnroot/jena/ARQ/

SPARQL is described in:
  http://www.w3.org/TR/rdf-sparql-query/
  
SPARQL-Update is described in:
  http://jena.hpl.hp.com/~afs/SPARQL-Update.html

== Status

The implementation of SPARQL is complete and meets the SPARQL Recommendation.

ARQ passes all the working group tests.

SPARQL W3C recommendation:
  http://www.w3.org/TR/rdf-sparql-query/

Definition of SPARQL:
  http://www.w3.org/2001/sw/DataAccess/rq23/rq25.html#sparqlDefinition

== Online Services

SPARQL syntax validator: 
  http://www.sparql.org/validator.html

SPARQL processor:
  http://www.sparql.org/sparql.html

== Support and Questions

Comments and questions about ARQ to the Jena mailing list 
    jena-dev@groups.yahoo.com

General questions and comments on SPARQL to jena-dev or
    public-sparql-dev@w3.org