libxml-dom-xpath-perl | adds XPath support to XML::DOM, using XML::XPathEngine | Mehr ...
XML::DOM::XPath allows you to use XML::XPath methods to query a DOM. This is often much easier than relying only on getElementsByTagName. It lets you use all of the XML::DOM methods. . In truth this should only be used if you have existing code using XML::DOM. If you start a new project and you can install XML::LibXML (and libxml2 on which it is based) then you will get a DOM, XPath support and a lot more power and speed.