Hello! If you're reading this guide, you're probably either a person looking to start up a translation site, and have it be recognized on the links page, or some other sort of extra-community site. As of the time of writing, we've really only looked at translation sites, but we're not at all opposed to other sorts of sites being recognized. Now, I'm going to go over the standards we have for these sites, and what you can do to make yours linked from our pages.
Most of the sites we link to are WikiDot sites. They don't exclusively have to be, though. In the past, before they migrated to wikidot, the Polish wiki used another site. The SCP-CN site currently uses the WikiDot software, to imitate the look and feel of the site, without actually using the WikiDot servers. Now, we strongly recommend that you use a WikiDot site because, despite its limitations, it is the easiest way to make sure members of the community can seamlessly flow from our site to yours.
When you first make your site, I personally recommend that you make it open for anyone to join. It might suffer from trolling or bad users, but it's the easiest way to make your community grow. Just make it so that only moderators can delete things, and you'll most likely be fine.
If you use a WikiDot site, you will also be able to copy and edit our theme. If you look at some of our hubs from the Groups Of Interest Contest, they have some heavily edited CSS. You should be able to make the minor alterations to your theme, in order to make it fit your site. If you have any trouble with it, contact our technical team for assistance.
You can copy all of our code for the Series 1, 2, and 3 pages, as well as any other technical pages you wish to use in order to imitate the look and feel of the main Foundation site. For those hub pages, just go to the "page source" option at the bottom of the page, and copy what you see. If you wish the use our theme, then check out This Page.
There is also a detailed guide on How to create a branch of the SCP-Foundation.