Repoze.what-xml is a project mainly written in Python, it's free.
The repoze.what 1.0 XML plugin
The repoze.what XML plugin
This is an adapters plugin for repoze.what.
A sample group source may look like this:
<?xml version="1.0" encoding="UTF-8"?>
A sample permission source may look like this:
<?xml version="1.0" encoding="UTF-8"?>