Grakn is a graph database written in Java.
Custom API
Graph Entity-Relationship
Grakn supports the entity-relationship model for graph datasets. Users can model type hierarchies, hyper-entities, hyper-relationships, and rules.
https://grakn.ai/
https://github.com/graknlabs/grakn
https://dev.grakn.ai/docs/general/quickstart
Grakn
GB
2016
Distributed Semantic Database
Commercial, Open Source
Java
Java, JavaScript, Python
Linux
AGPL v3