neo4j

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.

https://neo4j.com/