RSpec is a 'Domain Specific Language' testing tool written in Ruby to test Ruby code. It is a behavior-driven development framework which is extensively used in the production applications. The basic idea behind this concept is that of Test Driven Development where the tests are written first and the development is based on writing just enough code that will fulfill those tests followed by refactoring. It contains its own mocking framework that is fully integrated into the framework based upon JMock. The simplicity in the RSpec syntax makes it one of the popular testing tools for Ruby applications. The RSpec tool can be used by installing the rspec gem which consists of 3 other gems namely rspec-core, rspec-expectation and rspec-mock.