A toolkit of support libraries and Ruby core extensions extracted from the Rails framework. Rich support for multibyte strings, internationalization, time zones, and testing.

Rack provides a minimal, modular and adaptable interface for developing web applications in Ruby. By wrapping HTTP requests and responses in the simplest way possible, it unifies and distills the API for web servers, web frameworks, and software in between (the so-called middleware) into a single method call.

BDD for Ruby. RSpec runner and example groups.

rspec-expectations provides a simple, readable API to express expected outcomes of a code example.

RSpec's 'test double' framework, with support for stubbing and mocking

The mime-types library provides a library and registry for information about MIME content type definitions. It can be used to determine defined filename extensions for MIME types, or to use filename extensions to look up the likely MIME type definitions. Version 3.0 is a major release that requires Ruby 2.0 compatibility and removes deprecated functions. The columnar registry format introduced in 2.6 has been made the primary format; the registry data has been extracted from this library and put into {mime-types-data}[https://github.com/mime-types/mime-types-data]. Additionally, mime-types is now licensed exclusively under the MIT licence and there is a code of conduct in effect. There are a number of other smaller changes described in the History file.

Rack::Test is a small, simple testing API for Rack apps. It can be used on its own or as a reusable starting point for Web frameworks and testing libraries to build on.

rubyzip is a ruby module for reading and writing zip files

A minimal mime type library

A Ruby parser written in pure Ruby.

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

Capybara is an integration testing tool for rack based web applications. It simulates how a user would interact with a website

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

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

We use this library at GitHub to detect blob languages, highlight code, ignore binary files, suppress generated files in diffs, and generate language breakdown graphs.

Crass is a pure Ruby CSS parser based on the CSS Syntax Level 3 spec.

Erubi is a ERB template engine for ruby. It is a simplified fork of Erubis

This library can read and update netrc files, preserving formatting including comments and whitespace.

Generic connection pool for Ruby

WebMock allows stubbing HTTP requests and setting expectations on HTTP requests.