Neo4j is the world's leading Graph Database.  It is a high performance graph
store with all the features expected of a mature and robust database, like a
friendly query language and ACID transactions. The programmer works with a
flexible network structure of nodes and relationships rather than static
tables yet enjoys all the benefits of enterprise-quality database. For many
applications, Neo4j offers orders of magnitude performance benefits compared
to relational DBs.

WWW: https://neo4j.com