Ruby on Rails is described as 'Open source full-stack framework using Ruby, offering MVC architecture, Active Record ORM, scaffolding, secure defaults, RESTful design, and integrated testing' and is a popular Web Framework in the development category. There are more than 25 alternatives to Ruby on Rails for a variety of platforms, including Linux, Mac, Windows, Web-based and Self-Hosted apps. The best Ruby on Rails alternative is Django, which is both free and Open Source. Other great apps like Ruby on Rails are Laravel, Symfony, ASP.NET and Meteor.
It is not an alternative in a strict understanding, but rather installation wizard for any new Ruby on Rails project.