On Debian-based systems:

<notextile>
<pre><code>~$ <span class="userinput">sudo apt-get install runit</span>
</code></pre>
</notextile>

On Red Hat-based systems:

<notextile>
<pre><code>~$ <span class="userinput">sudo yum install runit</span>
</code></pre>
</notextile>