A toolkit for building modeling frameworks like Active Record. Rich support for attributes, callbacks, validations, serialization, internationalization, and testing.

Databases on Rails. Build a persistent domain model by mapping database tables to Ruby classes. Strong conventions for associations, validations, aggregations, migrations, and testing come baked-in.

Web apps on Rails. Simple, battle-tested conventions for building and testing MVC web applications. Works with any Rack-compatible server.

Ruby on Rails is a full-stack web framework optimized for programmer happiness and sustainable productivity. It encourages beautiful code by favoring convention over configuration.

Email on Rails. Compose, deliver, and test emails using the familiar controller/view pattern. First-class support for multipart email and attachments.

Rails internals: application bootup, plugins, generators, and rake tasks.

Simple, battle-tested conventions and helpers for building web pages.

Declare job classes that can be run by a variety of queuing backends.

Structure many real-time application concerns into channels over a single WebSocket connection.

Attach cloud and local files in Rails applications.

Edit and display rich text in Rails applications.

Receive and process incoming emails in Rails applications.

EXtended http(s) CONnections

Sprockets Rails integration

This gem can compare doms and assert certain elements exists in doms using Nokogiri.

URIs for your models makes it easy to pass references around.

bootstrap-sass is a Sass-powered version of Bootstrap 3, ready to drop right into your Sass powered applications.

factory_bot provides a framework and DSL for defining and using factories - less error-prone, more explicit, and all-around easier to work with than fixtures.

Spree Models, Helpers, Services and core libraries

rspec-rails is a testing framework for Rails 5+.