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.