Delayed_job (or DJ) encapsulates the common pattern of asynchronously executing longer tasks in the background. It is a direct extraction from Shopify where the job table is responsible for a multitude of core tasks. This gem is collectiveidea's fork (http://github.com/collectiveidea/delayed_job).

Eases web-request routing, handling, and response as a half-way front, half-way page controller. Implemented with specific emphasis on enabling easy unit/integration testing that doesn't require a browser.

Implements the ActiveRecord pattern (Fowler, PoEAA) for ORM. It ties database tables and classes together for business objects, like Customer or Subscription, that can find, save, and destroy themselves without resorting to manual SQL.

Wraps web resources in model classes that can be manipulated through XML over REST.

Rails is a framework for building web-application using CGI, FCGI, mod_ruby, or WEBrick on top of either MySQL, PostgreSQL, SQLite, DB2, SQL Server, or Oracle with eRuby- or Builder-based templates.