<blockquote>
 <p><strong>Possible Duplicate:</strong><br>
 <a href="http://meta.stackexchange.com/questions/28625/whats-the-joke-in-the-stack-overflow-404-page-code">What&#39;s the joke in the Stack Overflow 404 page code?</a> </p>
</blockquote>



<p>For example:</p>

<p><a href="http://stackoverflow.com/questions/does_not_exist">http://stackoverflow.com/questions/does_not_exist</a></p>

<p>What is the code on the right pane, and if it is a real language, what does it do exactly?</p>