Run any Ruby script from the context of a web request.

Rails-style method hooks for plain old Ruby objects

Plupload lets you upload multiple files at a time and even allows drag and drop from the local file system into the browser (with Firefox and Safari). This gem/plugin tries to make its integration with Rails 3 very simple.

Rails 3 version of has_friends gem

Lightweight configuration for your ruby app. Reads Rails-style YAML files from your config directory. Features include optional environment namespacing, local convention-based override files, and indifferent (symbol vs string) access.

Msgr: Rails-like Messaging Framework

Logs exceptions inside a database table. Now available as gem for Rails3 (previously a plugin for Rails2)

A linting tool that helps you find any routes defined in your routes.rb file that don't have a corresponding controller action, and find any _path or _url calls that don't have a corresponding route in the routes.rb file.

The Ajax.org Cloud9 Editor (Ace) for the Rails 3.1 asset pipeline.

CMS for Rails. For Reals.

A set of handy tools to upgrade your Rails application and keep it up to date

Action caching for Action Pack (removed from core in Rails 4.0)

Lookbook is a UI development environment for Ruby on Rails applications

XML parameters parser for Action Pack (removed from core in Rails 4.0)

Interactor Rails provides Rails support for the Interactor gem.

The Postmark Rails Gem is a drop-in plug-in for ActionMailer to send emails via Postmark, an email delivery service for web apps.

Provides a Jasmine Spec Runner that plays nicely with Rails 3.2 assets and sets up jasmine-headless-webkit

HSQLDB JDBC adapter for JRuby on Rails.

MS_SQL JDBC adapter for JRuby on Rails.

Derby JDBC adapter for JRuby on Rails.