ActiveObject
ActiveObject is an ActiveRecord- and DataMapper-inspired wrapper around Ruby object serialization.
Ambitious Ultrasphinx
An Ambition adapter to Sphinx, a full-text search engine.
Craps
A craps simulator to help you plan your next trip to the casino by minimizing the house advantage and setting basic constraints on your play.
Factory Girl
A gem that lets you easily define and use Factories in your test suite for ActiveRecord projects.
No Cache
Rails plugin. Force major browsers (IE, Firefox, Safari) to reload a page, even when triggered by 'back' button.
Paperclip
Paperclip is an easy file attachment library for ActiveRecord. Setup is easy and files are treated like other attributes on your model. They aren’t saved to their final locations on disk, nor are they deleted if set to nil, until ActiveRecord::Base#save is called. It manages validations based on size and presence, if required. It can transform its assigned image into thumbnails if needed, and the prerequisites are as simple as installing ImageMagick. Attached files are saved to the filesystem and referenced in the browser by an easily understandable specification, which has sensible and useful defaults.
ProxyDemocracy.org
Provides tools to help investors use their voting power to hold corporations accountable.
Quiet Backtrace
Quiets the noise in your Test::Unit backtrace.
Recommendable
A Rails plugin for Amazon.com-style item-to-item collaborative filtering.
Shoulda Gem
The Shoulda gem makes it easy to write elegant, understandable, and maintainable tests. Shoulda consists of test macros, assertions, and helpers added on to the Test::Unit framework. It's fully compatible with your existing tests, and requires no retooling to use.
Shoulda Rails
The Shoulda Rails plugin makes it easy to write elegant, understandable, and maintainable tests. Shoulda consists of test macros, assertions, and helpers added on to the Test::Unit framework. It’s fully compatible with your existing tests, and requires no retooling to use. Macros: Generate hundreds of lines of Controller and ActiveRecord tests with these powerful macros. They get you started quickly, and can help you ensure that your application is conforming to best practices. Assertions: Many common rails testing idioms have been distilled into a set of useful assertions.
Spec Factories
A generator to create Factories in your RSpec suite.
Squirrel
SQL Simplification Plugin for ActiveRecord This plugin extends the ActiveRecord::Base#find method to be able to take a block of Ruby which will get parsed into a nice SQL string and have its results returned.