Wikibase is the software that runs Wikidata, but is also usable for other projects beyond that. Wikibase allows the collaborative editing of structured data on top of MediaWiki.
ArangoDB database is an open-source NoSQL solution with a flexible data model for documents, graphs, and key-values.
Bitsy is a small, fast, embeddable, durable in-memory graph database that implements the Blueprints API.
A high-performance graph database implemented as a Redis module.
Content management system and web-based Rapid Application Development environment based on the graph database Neo4J. A commercial hosted version is also available at structr.com.
Titan is a scalable graph database optimized for storing and querying graphs containing hundreds of billions of vertices and edges distributed across a multi-machine cluster.
An embedded transactional graph engine for Python backed by a LMDB file. Works with Python 2.6, 2.7 and 3.x.
GraphStack ™ is the name for the Neo4j Enterprise open source distributions compiled and packaged from the official Neo4j Github Repository by the Graph stack.io Team.
An on-premise graph visualization and analysis software to investigate complex connected data.
FlockDB is a distributed graph database for storing adjancency lists, with goals of supporting:a high rate of add/update/remove operations
GraphDB is a RDF graph database or triplestore. It is the only triplestore that can perform semantic inferencing at scale allowing users to create new semantic facts from existing facts. It also has the ability to visualize triples.
AllegroGraph is a high-performance, persistent graph database. AllegroGraph supports SPARQL, RDFS++, and Prolog reasoning from numerous client applications.
Track anything and create insightful graphs. Find correlations or trends in your habits, behaviours, symptoms etc.
Crux is an open source document database with bitemporal graph queries.