PyXB (“pixbee”) is a pure Python package that generates Python source code for classes that correspond to data structures defined by XMLSchema. In concept it is similar to JAXB for Java and CodeSynthesis XSD for C++.
Paperboy WDM is a web development framework built around the concept of separating logic, content, and presentation without the complexities of SQL. It uses Paperboy RSS as a translation layer between content (in XML) and presentation.
XeriL is a java library that allows to turn a java object into an xml document and vice versa (DTD depends on the object). A powerful concept of mappers (extensible) can tailor the result to your needs. Very useful for configuration files.