Titan DB vs Neo4J

This comparison is an outdated comparison. I think Neo4J has improved a lot with the time. But I'm posting this because a person who wants to compare both of these technologies, can get an idea about the aspects they need to focus. If you know something is outdated please feel free to suggest using comments. I'll update the blog post accordingly.

FeatureNeo4JTitan
LicenseGPL/AGPL/CommercialApache 2 License
Commercial SupportAvailable
Advanced: Email 5x10 USD 6000/yr
Enterprise: Phone 7x24 USD 24,000/yr
Available (Prices and availability of support not published officially.)
Graph TypeProperty GraphProperty Graph
Storage BackendNative Storage EngineCassandra, Hbase, Berkeley DB
Depending on the requirement we should select Database Backend (eg: Cassandra for Availability and Partitionable, Hbase for Consistency and Partitionable)
ACID SupportYesACID is supported on BerkeleyDB Storage Backend
Has Transactions in Java API.On Cassandra Eventually consistent
ScalabilityCan't Scale-out like TitanOwns very good scalability
can scale like Cassandra if storage backend is cassandra
High AvailabilityReplication is the only way to have high scalabilityTitan is like API because of that Availability of Storage backend is the availability for graph database
Failover is not smoothIf we are using Cassandra with Titan No-Single-Point of failure. Extremely Available
Query LanguageCypher and GremlinGremlin
Cypher easy to learn but only suitable for simple queries.Gremlin has good algorithms to retrieve data in an optimal way. (+ More generic)
Graph Sharding Not Available, under developmentNot Available, under development
Support for languagesJava/.NET/Python/PHP/NodeJS/Scala/GOJava
Written inJavaJava
ProtocolHTTP/RESTCan expose REST using Rexster
Use casesmore than 10 available0 use cases exposed officially
Number of edges vertices supported2^35 (~34 Billion) Nodes (Vertices)2^59 Vertices
2^35 (~34 Billion) Relationships (edges)2^60 (quintillion) edges
2^36 (~68 Billion) Properties
2^15 (~32 000) Relationship types
LimitationsKey Index must be created prior to the key being used
Unable to drop key indices
For bulk graph operations we have to use Faunus otherwise storage backends get OutOfMemoryException
Types cannot be changed once created
Web AdminAvailableNot Available
EmbeddableYesYes
MapReduce-Yes with Faunus
Lucene Indexing SupportYesYes
BackupsYesYes (+Titan Parallel backup)

This link is also very useful - http://db-engines.com/en/system/Neo4j%3BTitan