Thanks for the info. So perhaps it's best to migrate the competition setup to Xenforo rather than moving the Xenforo to it. There has been a considerable amount of dev. already put into the competition site and it is working great, I just want to get a single signon. If this multisite won't work, can you recommend any other setup? Or can this be done customized for a fee? Thanks.@PJK ! Multisite System allows to create customized communities on a single XenForo database. From your description, it seems Multisite System will not help in your case. If you'll build a competitions website based on XenForo (with its nodes, style, etc.) and will want to have 2 domains, one for XenForo forum and one for competition site based on the same XenForo database, Multisite System will work for you.