[andrethegiant]

* Why feature detect classList with `if ("classList" in document.documentElement)` and not `!! document.documentElement.classList` like described at the beginning of the article?

* Why add a style to a cloned node instead of directly to the node? Performance improvements?

* `$ = document.querySelectorAll.bind(document);` won't let you have a shorthand for performing a query selector on an element. For that, you also need something like `Element.prototype.$ = Element.prototype.querySelectorAll;`. Likewise, you'll probably want the `on` shorthand applied to document and window too for consistency's sake.

* I also like to cast Array's forEach method to NodeList to iterate over values from a querySelectorAll. That way you can do $('a').forEach() instead of [].forEach.call($('a'), function(el)).

[Dunnorandom]

You could also just convert the NodeList to an array by running something like

    [].slice.call(nodeList)

That way you get all array methods, not just forEach.