rainbow

Colorize printed text on ANSI terminals

$gem install rainbow

Official docs outline

Extra Credit builds an outline of rainbow's docs the first time your work uses it. Until then, start at the official documentation.

actionmailer Email on Rails. Compose, deliver, and test emails using the familiar controller/view pattern. First-class support for multipart email and at
method_source retrieve the sourcecode for a method
mail A really Ruby Mail handler.
faraday-net_http Faraday adapter for Net::HTTP
rubocop RuboCop is a Ruby code style checking and code formatting tool. It aims to enforce the community-driven Ruby Style Guide.
ruby-progressbar Ruby/ProgressBar is an extremely flexible text progress bar library for Ruby. The output can be customized with a flexible formatting system
loofah Loofah is a general library for manipulating and transforming HTML/XML documents and fragments, built on top of Nokogiri. Loofah also inclu
racc Racc is an LALR(1) parser generator. It is written in Ruby itself, and generates Ruby program. NOTE: Ruby 1.8.x comes with Racc runtime
connection_pool Generic connection pool for Ruby
mime-types-data mime-types-data provides a registry for information about MIME media type definitions. It can be used with the Ruby mime-types library or ot
rails-html-sanitizer HTML sanitization for Rails applications
activejob Declare job classes that can be run by a variety of queuing backends.