I found this website some days ago, and I've been thinking about how they do it. Does anyone what kind of back-end they use for everything? Forums, changelog etc. Can't find anything in the codes, and I'm sure they've not made all this by themself.
ExpressionEngine, Twitter Bootstrap and?
Their CMS is : ExpressionEngine.
Their Content Delivery Network is : BootstrapCDN, Akamai and jQuery CDN.
Their forum tool looks to be in ExpressionEngine, probably a plugin.
I suggest using BuiltWith.com for these kinds of questions instead on stackoverflow.