neo4j - Meet Neo4j: The graph database platform powering today's mission-critical enterprise applications, including artificial intelligence, fraud detection and recommendations.
Redis - Redis is an open source in-memory data structure project implementing a distributed, in-memory key-value database with optional durability.
ArangoDB - A distributed open-source database with a flexible data model for documents, graphs, and key-values.
Azure Cosmos DB - NoSQL JSON database for rapid, iterative app development.
OrientDB - OrientDB - The World's First Distributed Multi-Model NoSQL Database with a Graph Database Engine.
Apache Cassandra - The Apache Cassandra database is the right choice when you need scalability and high availability without compromising performance.