Development is what computer engineers are known for. Just as the world is advancing new, web development software is being introduced. Each one of them is better than the previous ones. One such software is Sinatra, It is a free and open source web application library that is domain-specific and language. Sinatra is written in Ruby. Just like nitro, and ruby on rails, Sinatra is another such web application development alternative. It works on the Rack web server interface. In this section, we will be looking forward to what is Sinatra and its various features and basics. We will also explain how to develop a Sinatra Application.