librexml-ruby 3.1.2.1+ruby1.8.2-1 (amd64 binary) in ubuntu breezy

pure Ruby non-validating XML parser supporting Namespaces, XPath
 REXML is a XML parser for Ruby written purely in Ruby so you don't need to
 install any binary libraries. It includes a DOM-like API which fits the
 Ruby-way of human-oriented programming much more than the DOM and a
 SAX-like streaming API. Additionally you can apply XPath-expressions to the
 tree. REXML also has support for XML-Namespaces.
 .
 This package is a dependency package, which depends on Debian's default
 Ruby version (currently 1.8.x).