When I try to access http://m.mediawiki.org/wiki/MediaWiki, I intermittently get a completely white screen. If I refresh a few times, it'll sometimes load. It seems to be more commonly not loading than loading.
I'm using an iPhone 5 with iOS 6.1.4 and private browsing enabled. I tested with a friend's phone (iPhone 4 of some kind) and had the same issue. Not sure how to diagnose the issue from my phone.