GlobalID provides a way to generate URIs from a model in Ruby that uniquely identify it.

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

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.

Spring is a Ruby on Rails application preloader. It speeds up development by keeping your application running in the background so the application does need to boot it every time you run a test, rake task or migration.

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

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

Propshaft is an asset pipeline library for Rails. It's built for an era where bundling assets to save on HTTP connections is no longer urgent, where JavaScript and CSS are either compiled by dedicated Node.js bundlers or served directly to the browsers, and where increases in bandwidth have made the need for minification less pressing. These factors allow for a dramatically simpler and faster asset pipeline compared to previous options, like Sprockets.

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

Import maps can import JavaScript modules using logical names that map to versioned/digested files -- directly from the browser. It makes it possible to build modern JavaScript applications using JavaScript libraries made for ES modules (ESM) without the need for transpiling or bundling, which removes the need for Webpack, Yarn, npm, or any other part of the JavaScript toolchain. All that is needed is the asset pipeline that is already included in Rails.

Provides Sprockets implementation for the Rails Asset Pipeline.

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.

Sprockets is a Rack-based asset packaging system that concatenates and serves JavaScript, CoffeeScript, CSS, LESS, Sass, and SCSS.

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.

This gem is used to handle HTML sanitization in Rails applications. If you need similar functionality in non Rails apps consider using Loofah directly.

marcel provides MIME type detection using magic numbers, filenames, and extensions

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

This Ruby library integrates SassC-Ruby into Rails.

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

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

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.

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

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

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