August 21st, 2009
“Neo4j is a graph database. It is an embedded, disk-based, fully transactional Java persistence engine that stores data structured in graphs rather than in tables. A graph (mathematical lingo for a network) is a flexible data structure that allows a more agile and rapid style of development.”
From the site:
- graph-oriented model for flexible data representation;
- graph network consisting of nodes, relationships and properties;
- highly scalable to bilions of nodes/rels/props;
- can be sharded to scale out across multiple machines;
- hi-speed traversals in the node space;
- small footprint (500k jar)
- ACID transactions;
- robust persistence;
- concurrency control;
- Neo4j.rb, JRuby API;
- Lucene for quering and indexing.
Neo4j is released under a GNU Affero General Public License, so read carefully. There’s a price table for commercial products that includes severall support levels.