Driki

Driki is a module that was specifically created to import Wiki articles based on their XML version into nodes
(although it is possible to import just any XML).
This module provides a custom field widget that enables you to define an internal/external path
to your XML of the Wiki entry. Along with the URL Driki asks for a text format the results should be filtered with.
Ideally you will already have any standard or contributed filter that understands a certain Wiki syntax.
Driki will store the body of your XML, and do the filtering during output.