The SCP Foundation wiki is hosted on Wikidot, which provides free wiki hosting. It can be accessed either via a Wikidot subdomain or via the dedicated domain. Annoyingly, it seems like both alternate routes into the same content have about equal search engine optimisation, so a random SCP link has an even chance of using either domain.

I recommend using <http://scp-wiki.wikidot.com/> rather than the alternative. Wikidot has some problems with it; one of those is that some browsers have trouble logging in when the domain name isn't *.wikidot.com.

It's hosted on Wikidot. The bottom-left of the site says "Powered by Wikidot.com" and Wikidot wikis can be hosted on custom domains as well as subdomains of wikidot.com:

https://www.wikidot.com/features

The answer is at the end of OP page:

  Recommendations: It may be worthwhile to post at least one
  staff member capable of remembering the existence of
  SCP-055 to each critical site.