I'm not too familiar with the inner machinations of the Deep Web, but from my understanding it can only be accessed by certain browsers that obscure your IP address by using VPNs in several countries on at least 4 different nodes. The original Joy of Satan site is perfect for this, as it only uses basic HTML and css scripting. However, forums will have to function on the most basic level possible. Forums of any kind use a database system called MySQL, which is how this forum functions as well. You can tell from the URL, where it'd say "/page.php?topic=(number)" for example.
It's possible but it'll run very slowly.