Viewer sources are available in datagr4m-application module. To get a fresh build, checkout datagr4m repository, run
mvn install which produces
You can download the 1.0 version built in September 2013 (no continuous delivery yet). The archive contains a neo4j database (DoctorWho) and a few workspaces you might use as a starting point.
Simply unzip the archive and click run-datagram.bat.
The libraries sources are available on Github.
Maven repository stands here (deployed manually).