Ruby is a dynamic, general-purpose programming language. It has an elegant syntax that's natural to read and easy to write. It is cross-platform, it can run on a variety of platforms, including Linux, Mac OS X, Windows, iOS and Android. It is powerful, secure and easy to learn. A Ruby application can be easily developed by using the open source libraries. The libraries are the set of functions that are used by the programmers to develop a web application. Ruby has been used to write programs that control robots, drive cars, and help power the websites of such organizations as NASA, Twitter, and the New York Times. Developers tend to use some of the following Ruby Application open source libraries: activeadmin - The administration framework for Ruby on Rails applications; brakeman - static analysis security vulnerability scanner; draper - Decorators/ViewModels for Rails Applications.