This plugin was not made by me (Hoot215). I only contributed to it. The original page, and more information, can be found at this address:
http://forums.bukkit.org/threads/fun-volcano-v0-86-create-your-volcano-1060.25925/
Information on my modified version can be found here:
http://forums.bukkit.org/threads/fun-volcano-v0-86-create-your-volcano-1060.25925/page-3#post-626705