PlasTeX is a collection of Python frameworks that allow you to process LaTeX documents. This processing includes, but is not limited to, conversion of LaTeX documents to various document formats. Of course, it is capable of converting to HTML or XML formats such as DocBook and tBook, but it is an open framework that allows you to drive any type of rendering. This means that it could be used to drive a COM object that creates a MS Word Document.
The plasTeX framework allows you to control all of the processes including tokenizing, object creation, and rendering through API calls. You also have access to all of the internals such as counters, the states of "if" commands, locally and globally defined macros, labels and references, etc. In essence, it is a LaTeX document processor that gives you the advantages of an XML document in the context of a language as superb as Python.