TitanDB is dead in the water. They have been unresponsive since getting acquired by Datastax, it looks like the team is now working on their commercial offering. Everyone I know is looking for alternatives.
Re:Cayley – An open-source graph database
by wrabbitfoot on Wednesday June 15, 2016 @12:48AM
(#11907202)
the new Datastax product may be built on top of Titan.
http://intsantglobalnews.com/datastax-adds-graph-databases-t...
Re:Cayley – An open-source graph database
by scrollaway on Monday June 13, 2016 @09:10PM
(#11899086)
Dgraph looks pretty great.
https://github.com/dgraph-io/dgraph
http://titan.thinkaurelius.com/
https://www.arangodb.com/
http://orientdb.com/orientdb/