If you need to search an xml document specifying a default namespace, the libraries such as libxml2 etc. have problems to search for xpath expressions.
The following xpath expressions will ignore any namespace, just checking for the local name of the element:
In XPath 1.0
//*[local-name()='name']
Selects any element with “name” as local-name.
In XPath 2.0 you can use:
//*:name