title: Why does Rails say it cannot find a JavaScript runtime?
body: <p>I'm working through "<a href="http://guides.rubyonrails.org/getting_started.html" rel="nofollow">Getting started with Rails</a>."</p>
  
  <p>After creating the blog I got this error when I run <code>rails server</code>:</p>
  
  <pre><code>/usr/local/rvm/gems/ruby-2.0.0-p247/gems/execjs-2.0.1/lib/execjs/runtimes.rb:51:in "autodetect":
  Could not find a JavaScript runtime. 
  See https://github.com/sstephenson/execjs for a list of available runtimes. (ExecJS::RuntimeUnavailable
  </code></pre>
  
  <p>I added the 'execjs' gem to my Gemfile, but still got the same error. I reinstalled RVM, then reinstalled the gem, and all that I thought to solve the problem.</p>