Community

The graph-database ecosystem is growing fast.

Here a few places to check out.

TinkerPop

TinkerPop is a developers group that has built much of the open-source software stack for the emerging graph database landscape. It was co-founded by Marko Rodriguez, the creator of Rexster, Gremlin, Pipes, Frames, and Blueprints.

Rexster is a REST server that sits on top of the TinkerPop stack, and Stephen Mallette is one of its primary contributors. Because Bulbs connects to Rexster, by using Bulbs, you get access to everything TinkerPop provides:

https://github.com/tinkerpop/rexster/raw/master/doc/images/rexster-system-arch.png

Blueprints provides the foundation and a common interface to graph databases, which means your code is portable because you can to plug into different graph database backends without worrying about vendor lock in.

Here are some graph databases that have Blueprints implementations:

The Gremlin Users Group is the primary discussion forum for anything related to the TinkerPop stack, including Gremlin, Rexster and graph databases in general (go here first).

HansanB made this comment the other day comparing TinkerPop to the how it was in the early days of JServ/Tomcat:

Something like 13 yrs ago, I was trying to do server-side Java.  It
was a nightmare, until I discovered a thing called Apache JServ.

It was simple, elegant and the developer group was wonderfully
supportive and well organized.

Just as with JServ, way back then, Tinkerpop has all the same
characteristics, and gives me the same feeling of having hit on
something really valuable that will take me a long way.

Well ...  JServ morphed into TomCat, and I've used it consistently
ever since.  I'm confident Tinkerpop is going the same way, so I'm
only too pleased to help where I can.

Sincerest regards,
Hasan

To get a feel for graphs, watch these videos by Marko:

Neo4j

Neo4j is one of the leading open-source graph databases. The Community Edition is now free, and it can store 32 billion nodes while traversing 2 million relationships per second.

Peter Neubauer is a Neo4j co-founder and also a co-founder of TinkerPop. You can check out the entire Neo4j team on Github.

When you ask a question on the Neo4j User Group, you usually get a response within a few minutes.

Watch this video on Neo4j for quick overview.

OrientDB

OrientDB is an open-source graph database getting ready to release it’s 1.0.

Luca Garulli is the project lead, and active discussions are always going on at the OrientDB discussion group.

InfiniteGraph

InfiniteGraph is a distributed graph database based on the Objectivity object database. The free version is limited to 1 millions nodes.

A Blueprints-enabled InfiniteGraph implementation is scheduled for release in early 2012.

Watch these videos and presentations for an introduction. The InfiniteGraph developer forum is on Google Groups.

Dex

Dex is a graph database that originated at the Data Management group at the Polytechnic University of Catalonia (DAMA-UPC). It was spun-off into Sparsity-Technologies in March 2010.

There’s a free community version for academic or evaluation purposes available for download. The free version is limited to 1 million nodes, but there is no limit on edges.

OpenRDF

OpenRDF is the home for Sesame and related applications.

Sesame is the “de-facto standard framework for processing RDF data.” It provides an easy-to-use API that can be connected to most of the leading RDF data stores.

You can subscribe to the Sesame mailing list here.