Neo4j Wiki から
 Native API
There are several ways to access the Java API from Ruby, using the JRuby-Java bindings, with Ruby wrappers to make life easier. The most popular of these is the neo4j.rb gem, and there is a complete guide for that in Getting Started With Ruby. Below we have a more complete list many known alternatives.
Neo4j.rb is a graph database framework for JRuby built on top of the Neo4j Java library. It supports creating RESTful APIs, see the GitHub page.
- @github by Andreas Ronge
- Rails example @github
- Mini recommendation engine example
- presentation slides from RubyManor 2008
A simple, ready to go JRuby wrapper for the Neo4j graph database engine.
- neo4jr-simple by Matthew Deiters
- neo4jr-simple at gemcutter
- neo4jr-social by Matthew Deiters. Neo4jr-Social is a self contained HTTP REST + JSON interface to the graph database Neo4j. Neo4jr-Social supports simple dynamic node creation, building relationships between nodes and also includes a few common social networking queries out of the box.
neo4jr_gen is a Rails plugin that provides generators for creating neo4jr based resource scaffolds.
This is an experimental library for playing with an ActiveModel-charged version of the Neo4j Ruby library. The intent is to use it as a full replacement for ActiveRecord inside a Rails 3 application.
 REST API
Since the release of the REST API, and the subsequent release of the Neo4j Server, it has also become possible to use Ruby to access Neo4j through REST. This also means that you can use normal C-Ruby for Neo4j. There are two main possibilities, raw REST clients like RestClient, and neo4j-specific REST clients like Neography. Read more about these on Using the Neo4j Server with Ruby.