Ruby on Rails is a web application framework written in Ruby. It is a full-stack framework, meaning it provides both the front-end and back-end of an application. It has been around since 2004. It is free and open-source software that was created by David Heinemeier Hansson, who was also the co-founder of Basecamp.

It is one of the most popular web frameworks in use today. The Ruby on Rails framework provides a robust set of tools for developing web applications. It includes everything from an integrated development environment to scaffolding tools, testing frameworks, and generators for creating models and controllers.

Rails can help developers create high-quality web applications more quickly than if they were to use other frameworks, like PHP or ASP.NET Framework. Rails can be accessed through the command line, but it also has many tools for developers who prefer to work within an IDE environment, such as RubyMine