This isn't MediaWiki....

How do I make the slug show something that looks more like the MediaWiki screenshot on your website at:

Basically I'd like to make the /wiki/ slug an editable landing page with features pages and areas of the wiki, an editable hierarchical sidebar nav not linked to my existing sidebar, etc. But out of the box it's nothing like what I was expecting.

So I guess basically what I'm looking for is something that's a little bit more like MediaWiki, but easier to use.