SPARQL

A SQL-like query language for RDF. Very handy for AJAX applications as it supports HTTP and JSON.

An OSS Java implementation using Jena and packaged with Jetty: http://sparql.org

From the Opera web browser folks: http://my.opera.com/community/sparql/

JSON and graphs

The JSON result format is only for result sets (tablular select queries). Dan Connolly mentions the desire for handling more general results.

See Also

DemoOOHTML