Neo4j, is a labelled, property graph database with a native engine that is targeted at operational and hybrid operational/transactional and analytic use cases. Morpheus for Apache Spark allows you to map relational views into an in-memory Spark graph.
Neo4j is, in effect, the Oracle or SQL Server of the graph database world. From a generic perspective, graph databases are a natural home for combining operational and transactional processing with analytics. Their understanding of relationships, combined with the fact that is no need for multi-temperature data and no requirement to store the data twice (once in memory and once on disk) makes graphs an obvious candidate for processing in hybrid environments.