Neo4j is a high performance graph database that I usually use with the JRuby neo4j gem and sometimes with Clojure (documentation here).
Neo4j is open source (AGPL v3) and is alternatively available for a reasonable fee with a commercial license (where you don’t need to AGPL your project). I took advantage of the free offer to get your first Commercial Basic Server license, even though I am likely to open source my project anyway.
Hi Mark, what characterizes your uses of neo4j vs your uses of rdf/sparql/etc.?
Hello Patrick,
RDF data stores support SPARQL queries: good for matching patterns in data.
Neo4j supports arbitrary graph structures and seems best for exploring a neighborhood of a graph: start at a node and explore the connected nodes. (graph traversal)
Franz added support for social graph like search in Allegrograph 4 but a graph database like Neo4j still seems like a more natural fit.
Although both AllegroGraph and Neo4j are commercial products, each has a path for limited free commercial use. The free version of AllegroGraph RDFStore Server Edition is limited by a 50 million triples maximum. I got a free 1 server license for Neo4j so I can use it on a project small enough to fit on one server.
Both are great tools.
Hi Mark
The free version of AllegroGraph can only be used commercially for evaluation — see clause 2(5).
Cheers
Gary