At one point in our system we use javascript to read in a chunk of XML and then query that XML document using xPath.
Prior to IE 11, IE supported using xmldoc.select
To expand on pixelmatt's answer, some results of my tests (Win 7 64bit with IE11) I did in order to get DOMParser to work as it did in IE9 and IE10 (in IE11 it now returns an XMLDocument object which appears to not support xpath queries?).
Turns out I could make it behave like in IE10 with the following meta tag:
Results without and with above meta:

And here are the XMLDocument's memebers (for reference):
