Develop new content type for xml to html translation (Drupal 6)
Here is an idea that will keep coding to a minimum using already existing modules:


Using CCK if D6 or the fields if D7 create a regular content type and add an extra field for the XML as I will use the automatically added body to store the XSLT. On the content type display section hide the XSLT field, this way the data is collected, but it is not shown when the node is been view.
I will install the custom formatter module to create a text formatter where I can apply the XSLT to the XML and then present it as HTML.
If I can not apply the formatter directly to the body field in the content type display settings I will the hide both fields (body &amp; XSLT) and using views attachment in D6 or EVA in D7 attach the body field with the formatter applied to the content type.
Last but not least if I plan to re-use this setup in others sites I will use the "Features" module to exported.