Compose, deliver, receive, and test emails using the controller/view pattern. Including support for multipart email and attachments.

This package provides support for using RSpec to test Ruby on Rails applications, in pace of the default Minitest testing library.

Action Cable integrates WebSockets with Rails applications. Through WebSockets it allows for real-time features in web applications.

railties provides the core Rails internals including handling application bootup, plugins, generators, and Rake tasks.

This package allows you to create an interactive Ruby session in your browser. Those sessions are launched automatically in case of an error and can also be launched manually in any page.

ActionMailbox receives and processes incoming emails in Rails applications.

ActiveSupport is a toolkit of support libraries and Ruby core extensions extracted from the Rails framework. It includes support for multibyte strings, internationalization, time zones, and testing.

This Ruby library integrates SassC-Ruby into Rails.

This package provides a modest JavaScript framework for the HTML you already have.

The With advisory lock gem adds advisory locking to ActiveRecord for PostgreSQL and MySQL. SQLite is also supported, but this uses the file system for locks.

Bootsnap is a library that plugs into Ruby, with optional support for YAML, to optimize and cache expensive computations.

This package provides a toolkit for building modeling frameworks like Active Record. ActiveSupport handles attributes, callbacks, validations, serialization, internationalization, and testing.

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.

This package provides a Ruby wrapper for the MRI 2.0 debug_inspector API.

Active Record connects classes to relational database table to establish an almost zero-configuration persistence layer for applications.

ActiveJob allows declaring job classes in a common way across Rails applications.

Turbo aims to be as fast as single-page web application without having to write any JavaScript. Turbo accelerates links and form submissions without requiring server-side changes to the generated HTML. It allows carving up a page into independent frames, which can be lazy-loaded and operated as independent components. Finally, it helps making partial page updates using just HTML and a set of CRUD-like container tags. These three techniques reduce the amount of custom JavaScript that many web applications need to write by an order of magnitude. And for the few dynamic bits that are left, Stimulus can be used.

ActionView provides conventions and helpers for building web pages in Ruby.

This gem can compare HTML and assert certain elements exists. This is useful when writing tests.

This library integrates the SASS stylesheet language into Ruby on Rails.

This gem provides Ruby and Ruby on Rails integration with Autoprefixer, which can parse CSS and add vendor prefixes to CSS rules using values from the Can I Use website.

ActionText edits and displays rich text in Rails applications.

ActiveStorage integrates file storage services with Rails applications, allowing files to be attached to ActiveRecord models.

The ammeter gem makes it easy to write specs for Rails generators. An existing user is rspec-rails, which uses ammeter to spec its own generators.