Neo4j

Neo4j is a graph database management system developed by Neo4j, Inc. Described by its developers as an ACID-compliant transactional database with native graph storage and processing,[3] Neo4j is the most popular graph database according to DB-Engines ranking,[4] and the 21st most popular database overall.[5] Neo4j is available in a GPL3-licensed open-source "community edition", with online backup and high availability extensions licensed under a closed-source commercial license.[6] Neo also licenses Neo4j with these extensions under closed-source commercial terms. https://en.wikipedia.org/wiki/Neo4j