Neo4j is an open-source graph database management system developed by Neo4j, Inc. It is written in Java and Scala and is designed to store, manage, and query highly connected data. It is a NoSQL database that uses a graph structure with nodes, edges, and properties to represent and store data. Neo4j has a powerful query language called Cypher which makes it easy to find, filter, traverse, and manipulate data. Neo4j also offers an in-memory database, a cloud-based version, and a powerful visual interface to explore the data. It is used for a wide range of applications, including social networks, recommendation engines, fraud detection, and bioinformatics.
ArangoDB
Orient DB
Titan Database
RedisGraph
AllegroGraph
Flockdb
Dgraph
GraphStack.io
LemonGraph
Trinity Graph Engine
NetworkX
graph-tool
Discontinued Last updated on github in 2012