title: How do I upgrade the Ruby version of my project?
body: <p>I recently started learning Rails using Ruby 1.9.3p385, and I'm trying to develop a small project with it.</p>
  
  <p>I'm using Linux so I installed Ruby using RVM. </p>
  
  <p>I developed a few pages, following some tutorials. I would like to upgrade my project to use Ruby 2.0.0. What do I have to do?</p>
  
  <p>I installed Ruby 2.0.0 with RVM:</p>
  
  <pre><code>rvm install 2.0.0
  </code></pre>
  
  <p>Everything seems OK, so I tried to use it:</p>
  
  <pre><code>rvm use 2.0.0-p247
  </code></pre>
  
  <p>But when I try to run my Rails server using <code>rails server</code>, I get the following message:</p>
  
  <pre><code>bash: rails : command not found
  </code></pre>
  
  <p>I've read the <a href="http://rvm.io/rubies/upgrading" rel="nofollow">RVM documentation about upgrading Ruby</a> but I don't really understand what it does; I'm afraid of breaking everything.</p>
  
  <p>Does it will upgrade my project in a way it will use Ruby 2.0.0 or what should I do?</p>
  
  <p>Next, I will want to upgrade also to Rails v4.</p>