This concern maintains the illusion that a given object has specified attributes, when those attributes are in fact attached to an associated object. This is particularly useful for different classes within a single-table inheritance table to have access to separate fields in class-specific associations.

Scaffold Generator for Rails 3.2 and Sencha Extjs 4.1

Provides a simple way to include and manage release notes for internal applications by writing a markdown file

Facebook Connect integration library for ruby and rails

Enables easy table rendering in rails applications

Give your users the ability to manage their email subscriptions in your Rails application.

A gem to generate documentation out of tests.

Extensions for Finder classes

Rails 3+4 firewall route constraints for keeping the bad guys out.

Automatically allow Google-crawling and new visitors to your application access to content without requiring sign-in.

Plugin for read-only content websites with MongoDB storage. Works perfect with Rambler&Co CQRS projects

Integration of popular Rails/Spree store framework with e-commerce Flow API

Helpful form builder used by Rocketeers

Complex format validators

Formtastic extension that does client side form validation

courtesy - Wikipedia: Maker-checker (or Maker and Checker, or 4-Eyes) is one of the central principles of authorization in the information systems of financial organizations.The principle of maker and checker means that for each transaction, there must be at least two individuals necessary for its completion. While one individual may create a transaction, the other individual should be involved in confirmation/authorization of the same. Here the segregation of duties plays an important role. In this way, strict control is kept over system software and data, keeping in mind functional division of labor between all classes of employees.

Store the world's knowledge in Rails models (via Freebase)

Decouple your forms from your domain models

Decorate objects for presentation. Supports Rails out of the box.

Fuel's goal is to be a simple yet customizable blogging gem.