These are different versions of the old M.A.C. site.  The acronym means "Myriad of Allied Clansmen."  Versions 3 and 4 were concept sites that never went public.  The "intro" directory is the old M.A.C. portal for when we were planning to branch out into different games.  At one point we had a Warcraft 3 division on the portal that was going to be lead by a guildie, but that page was never developed.  Otherwise it was always just Diablo 2.