Wiki/Info pages

So, I was wondering, are there any add-ons that supply the ability to create a wiki-like info page. A page something like this. I would make one myself, but I honestly don't know if I have the time. And this is probably what would convince me to buy my own license.

Also, are then any light, sky sort of themed themes around? Or just a nice clean modern light blue theme?

Thanks guys!
Ok, I've got one more question. Can my license only be used on a single domain/subdomain? Or can it be used on multiple subdomains of the same domain? So for example, if I installed XenForo on would I then be allowed to use the same license to install it in and

Again, thanks for answering my questions guys! :D