title: require 'rubygems'
body: <p>I have seen many samples of Ruby code with this line (for example, <a href="http://www.sinatrarb.com/" rel="noreferrer">http://www.sinatrarb.com/</a>). What is purpose of this require?</p>
  
  <pre><code># require 'rubygems'
  require 'sinatra'
  get '/hi' do
    "Hello world!"
  end
  </code></pre>
  
  <p>In all cases the code works without this line.</p>