The Ruby Programming Language
JRuby, an implementation of Ruby on the JVM
A Ruby framework for building telephony applications
A tagging plugin for Rails applications that allows for custom tagging along dynamic contexts.
Textmate bundle for RSpec.
Experiment Driven Development for Ruby
Ruby on Rails
Simple Rails app configuration
optional scripts for hubot, opt in via hubot-scripts.json
A streaming JSON parsing and encoding library for Ruby (C bindings to yajl)
Project management and code hosting application. Follow us on twitter @gitlabhq
Rails 3 Plugin that tracks impressions and page views
OAuth for Ruby
Rspec-2 runner and formatters
Rspec-2 doubles (mocks and stubs)
Rspec-2 expectations (should and matchers)
Rspec-2 for Rails-3
Ajax.org Cloud9 Editor
Twilio API client
A Ruby gem for communicating with the Twilio API and generating TwiML
The Ruby community's gem hosting service.
The Travis-CI Worker
A distributed build system for the Ruby community
CRUD through HTTP is a good step forward to using resources and becoming RESTful. Another step further into it is to make use of hypermedia-based services and the Restfulie gem allows you to do it very quickly.
Ruby library for consuming Google, Yahoo!, Flickr and Windows Live contact APIs
Organise ActiveRecord model into a tree structure
Helper shell scripts to automate things we often do
Why's Poignant Guide to Ruby