1. Function to String conversion produces different results in different browsers.

  var f = []['concat']; (f + ''); 
  // Chrome
  "function concat() { [native code] }"
  // IE (9)
  "
  function concat() {
    [native code]
  }
  "

This script tries to extract letters from that string representation, which fails if the string is different. (This is also used as an anti-debugging measure in some JS malware, to prevent researchers from replacing document.write with alert() or similar.)

2. Iterating over the window object doesn't work the same way in IE: http://blogs.msdn.com/b/ericlippert/archive/2005/05/04/41468...

In particular, this script tries to extract strings 'sessionStorage', 'getComputedStyle', 'onchange' by iterating over the window object, all of whom fail in IE.

There are a couple of things that chrome do and other browsers do not. If you are really interested, its possible to do in other browsers by changing a few values, I was simply too lazy.