Some of the popular graph databases are Neo4J, Orient DB and Apache Titan (Titan: Big Graph Data with Cassandra).
Neo4j Community Edition : GPL v3 license, About Neo4j Licenses
license: 30 day trial
OpenCypher, une initiative de Neo4j et d'autres contributeurs vise à étendre l'emploi de Cypher à d'autres base de données orientées graphe3
Autre langage déclaratif pour les requêtes sur des données orientées graphe
GraphX is Apache Spark's API for graphs and graph-parallel computation.
GraphX is a new component in Spark for graphs and graph-parallel computation. At a high level, GraphX extends the Spark RDD by introducing a new Graph abstraction: a directed multigraph with properties attached to each vertex and edge. To support graph computation, GraphX exposes a set of fundamental operators (e.g., subgraph, joinVertices, and aggregateMessages) as well as an optimized variant of the Pregel API. In addition, GraphX includes a growing collection of graph algorithms and builders to simplify graph analytics tasks.
Apache Giraph is an iterative graph processing system built for high scalability. For example, it is currently used at Facebook to analyze the social graph formed by users and their connections. Giraph originated as the open-source counterpart to Pregel, the graph processing architecture developed at Google and described in a 2010 paper
Linkurious.js is an active fork of Sigma.js. It's dual-licensed under both GPLv3 and a commercial license for proprietary projects.
A graph visualization application for the web
Plugin sigma.neo4j.cypher provides a simple function, sigma.neo4j.cypher(), that will run a cypher query on a neo4j instance, parse the response, eventually instantiate sigma and fill the graph with the graph.read() method.
Plugin sigma.parsers.gexf provides a single function, sigma.parsers.gexf(), that will load a GEXF encoded file, parse it, and instantiate sigma.