If I understood it correctly,
the most up-to-date version of Xalan-Java still implements XPath Version 1.0.
http://xml.apache.org/xalan-j/
why is so? why it has not been updated to xpath2.0?
http://www.w3.org/TR/xpath20/
is there a similar library that implements xpath 2.0?
You can use saxon for xpath2.0. Xalan has prototype for it but this is not an
official build, see http://www.stylusstudio.com/xsllist/200212/post70030.html