Graph Databases edit 
Our list of and information on commercial, open source and cloud based graph databases, including Neo4j, OrientDB, JanusGraph and alternatives to these. Operational (OLTP) databases designed to support labelled property graph data models, where nodes and relationships have labels (types) and lists of property name-value pairs. Focus is on transactional ACID inserts/updates and traversal queries using index free adjacency (allows direct navigation between nodes without the use of indexes) over subsets of data rather than batch analytics over all data. Populate query interfaces/languages include Cypher (originated with Neo4J but now open source) and TinkerPop Gremlin (part of the TinkerPop framework that provides query capabilities and graph analytics over graph data). The Morning Paper review of the “Do we need specialized graph databases? Benchmarking real-time social networking applications” paper from the University of Waterloo, Ontario from May 2017 is worth a read before you go any further - this covers a number of use cases where relational databases perform better than dedicated graph databases, and also looks at the performance impact of using TinkerPop over a native API - https://blog.acolyer.org/2017/07/07/do-we-need-specialized-graph-databases-benchmarking-real-time-social-networking-applications/ DB Engines has a list of graph databases at https://db-engines.com/en/ranking/graph+dbms The following analyst material covers a number of technologies in this category: And Neo4j have a number of eBooks available for free download from https://neo4j.com/ and https://neo4j.com/books/, including a copy of O’Reilly’s Graph Databases. See the note above on the “Do we need specialized graph databases? Benchmarking real-time social networking applications” paper and the performance impact of using Apache TinkerPopCategory Definition
Further Information
Query Languages / Interfaces
Cypher Graph query language, originally from Neo4j, now open source and used by a wide range of graph databases, with out of the box packages for running Cypher jobs over Spark and TinkerPop Gremlin - http://www.opencypher.org/ TinkerPop Gremlin Query interface that uses low level adapters to execute graph traversals against any compatible graph databases - https://tinkerpop.apache.org/gremlin.html Commercial OLTP Graph Databases
Neo4j ACID-compliant transactional database with native graph storage and processing; open source with commercial edition; utilises Cypher - https://neo4j.com/ SAP OrientDB Multi-model (key-value, graph and document) NoSQL database with TinkerPop support and both community and enterprise editions - http://orientdb.com/graph-database/ ArrangoDB Multi-model (key-value, graph and document) NoSQL database with ACID transactions, TinkerPop compatibility and it’s own AQL query language with support for cluster deployments (including running over Mesos) - http://www.arangodb.com Sparksee Graph database formally known as DEX, with support for a range of languages and use on mobile devices and TinkerPop support- http://www.sparsity-technologies.com/ AgensGraph Commercial multi-model (relational and graph) databases - http://www.agensgraph.com/ Redis Graph Graph database over Redis that supports a subset of neo4j’s Cypher query language - http://redismodules.com/modules/redis-graph/ Open Source OLTP Graph Databases
Dgraph Open source graph database written in Go - https://dgraph.io/ HyperGraphDB Open Source Java graph database - http://hypergraphdb.org InfoGrid Open Source Java graph database with support for building REST APIs over the top - http://infogrid.org/trac/ VelocityDB Open Source C# .NET embeddable/distributed graph database - https://velocitydb.com/ Apache S2Graph (Incubating) OLTP graph database built on Apache HBase - https://s2graph.incubator.apache.org/ HGraphDB Open Source implementation of TinkerPop API for Apache HBase - https://github.com/rayokota/hgraphdb Sqlg Open Source implementation of TinkerPop API over relational databases - http://www.sqlg.org/ Unipop Open source TinkerPop API over a range of backends including Elasticsearch and JDBC https://github.com/unipop-graph/unipop Commercial OLTP/Analytical Graph Databases
DataStax Enterprise Commercial product built on Apache Cassandra with the addition of graph and search capabilities - https://www.datastax.com/ TigerGraph Commercial hybrid OLTP/OLAP graph database that claims order of magnitude performance and scalability improvements over it’s competitors; previously known as GraphSQL - http://www.tigergraph.com, http://www.zdnet.com/article/tigergraph-a-graph-database-born-to-roar/ GraphBase Commercial graph database supporting operational and analytical use cases designed for use in AI applications - https://graphbase.ai/ GRAKN.AI Open Source graph database designed for AI use cases that also supports graph analytics - https://grakn.ai Complexible Stardog RDF database that also support property graphs and data virtualisation, with a community edition available - http://www.stardog.com/ Open Source OLTP/Analytical Graph Databases
JanusGraph Open source distributed graph database that runs over a number of storage backends (including Cassandra, HBase and BigTable), with TinkerPop support including support for graph analytics; previously known as Titan - http://janusgraph.org/ TinkerGraph In memory graph databases that’s part of TinkerPop as a reference implementation, supporting both TinkerPop OLTP and OLAP use cases - http://tinkerpop.apache.org Combined Graph/RDF Databases
OpenLink Virtuoso Universal Server Supports persistence of documents, relational, RDF and graph data - https://virtuoso.openlinksw.com/ Franz AllegroGraph Commercial ACID compliant that supports both RDF and property graphs, with a free edition available - https://allegrograph.com/allegrograph/ BlazeGraph Open Source RDF graph database with property graph features, queryable via SPARQL and Tinkerpop - https://www.blazegraph.com/ Graph Databases as a Service
Microsoft Azure Cosmos DB Massively scalable, low latency multi-model (key-value, graph, wide column and document) NoSQL database, including support for the Gremlin API - https://azure.microsoft.com/en-us/services/cosmos-db/ IBM Graph Graph database as a service built using JanusGraph - https://www.ibm.com/us-en/marketplace/graph Amazon Neptune Graph and RDF database service with support for TinkerPop Gremlin and RDF SPARQL - https://aws.amazon.com/neptune/ Historical / Deprecated Graph Databases
Objectivity InfiniteGraph End of life, with functionality being migrated into Objectivity/DB and ThingSpan - http://www.objectivity.com/products/infinitegraph/ FlockDB Open Source distributed graph database from Twitter, however no longer maintained - https://github.com/twitter-archive/flockdb GlobalsDB Open Source, now dead - https://github.com/Globals/GlobalsDB Blog Posts