taxonomy_xml 5.x-2.x-dev

This includes a major rewrite, to support alternative syntaxes.
You can now use the original XML schema, CSV or RDF files to import vocabularies.
XML or RDF exports (not CSV yet) are possible.

This has been working fine on various sets of test data, but there may be some problems still to be found, eg character encoding or small parsing errors.
To be sure of the integrity of your data, you are advised to create an export immediately after a successful import. Comparing those files (they should contain identical information) may expose any irregularities.