Internal Program Version: XML::XPathEngine  0.14.5.42.0

This module provides an XPath engine, that can be re-used by other
module/classes that implement trees.

In order to use the XPath engine, nodes in the user module need to mimick
DOM nodes. The degree of similitude between the user tree and a DOM
dictates how much of the XPath features can be used. A module implementing
all of the DOM should be able to use this module very easily (you might
need to add the cmp method on nodes in order to get ordered result sets).

http://search.cpan.org/dist/XML-XPathEngine