A very fast & simple Ruby web server
Thin is a small and fast Ruby web server that is easy to install and configure for running Rack applications. It offers flexibility with many options that can be specified at the command line.
Ruby on Rails, often referred to as Rails, is an open-source web application framework written in Ruby. Known for its convention over configuration and don't repeat yourself (DRY) principles, Rails simplifies and accelerates the development of database-backed web applications.