Forum:Lostpedia's "Theory" tab - how'd they do it?

Lostpedia has an extra tab on their articles: Article, Discussion, and Theory. See Miles Straume for an example. I can see where it is in the source of that page, but not how to get there. This is their monaco.css, which I notice has tabview, but going by the Wikia help files on it, I'm guessing that's something else entirely. Is this feature unique among wikia wikis or does anyone know of others that have done something similar? --User:Mnenyver 06:17, 3 June 2009 (UTC)
 * Theory tab extension--