This is awesome, really. Are you inspired by the http://sites.fed.wiki.org/ design? Maybe they could take some ideas of yours, like the ability to close articles and the top bar navigation.
However, this could gain a lot with a click handler at each page on the sides that made the thing scroll into view again.
No, I haven't seen this one! That's incredible how similar the designs are. I just really enjoy the narrow column as it makes the article more readable. I'll reach out to them. Thanks!