The Dream Theater FAQ was created back in 1993 by Mike Bahr and Jason Hough on the Ytsejam Mailing List. The original posts are no longer available, but some very early FAQ-related posts can be read here and here.
Between 1993 and 1996 the history of the FAQ is very murky, but we do know that around 1996 Chris Merlo took over administration duties, and in 1998 he in turn left it for Pat Griffin to maintain (news item from DT.net about the transition). Pat created the graphical version of the site (still accessible here) that lasted until 2000, but dropped off the face of the internet shortly after that, leaving the FAQ dormant with no one taking responsibility for it.
Completely unaware of the FAQ's story to that point, I discovered the wealth of information that was the DT FAQ but was dismayed to learn that it hadn't been updated with any SFAM-related questions. I learned that no one was in charge of the FAQ, so I claimed it for myself and set about moving it to my own server (and the DTFAQ.com domain) with the help of Nick MacLean, a friend of mine.
We updated some of the old questions and added a bunch of new ones, but it was still essentially the same static information source that it had been for almost 10 years to that point. I decided that allowing people to post comments/updates to the answers in the FAQ would be a very valuable addition, so over the next few months I completely re-structured the site with a focus on community collaboration. That was DTFAQ.com v2, the biggest structural change in the FAQ's history since the move to the WWW - and v3 saw even more feature additions, the most well-received of which was the search engine. Further upgrades were made with v4, a redesign and restructuring of the FAQ.
By 2007, the original domain (dtfaq.com) expired and the site saw a move to the site of the norwegian fanclub, DTNorway. The site also changed owners - and is now in hands of the DTNorway staff.