ModelToJSON in the package (org.hyperdata.scute.rdf) is a serializer from Jena models to the 
JSON syntax described at http://www.w3.org/wiki/TriplesInJSON

Latest version:
https://github.com/danja/Scute/blob/master/src/org/hyperdata/scute/rdf/ModelToJSON.java

This directory contains support/example files for it.

rdfxml2jt is a script to convert RDF/XML into the JSON format.

example.js shows how the format can be used in Javascript 
(this example is for node.js, but the principle will be the same with other engines)