Ruby

Ruby on Rails

Web framework originally developed for 37signals's Basecamp application. It features "convention over configuration" for rapid prototyping and is currently on version 4.0.

Ruby testing tools

RSpec, Capybara, Watir, Cucumber.

RVM

Stands for Ruby Version Manager. A command-line tool designed to manage multiple installations of Ruby on the same device and easily switch between them. 

Sidekiq

Background processing framework for Ruby. Multi-threaded background job and message processing gem.

Sinatra

DSL for quickly creating web applications in Ruby. It is an alternative to other Ruby web application frameworks such as Ruby on Rails, Merb, Nitro, and Camping. It is dependent on the Rack web server interface. Light weight, very flexible, quick for creating web apps and with minimal effort.

Watir

A toolkit for automating tests. Watir interacts with a browser the same way people do: clicking links, filling out forms and validating text. It uses the Ruby scripting language to drive Internet Explorer, Mozilla Firefox, Google Chrome, Opera and Safari, and is available as a RubyGems gem.

WEBrick

A non-scalable Ruby library that provides web services. WEBrick can be used to create HTTP, HTTPS, proxy and virtual host servers. It uses the language of servlets to handle Ruby Blocks, CGI scripts, ERb pages, and directory listings on a per-path or per-host basis.