BibteXML is a bibliography schema for XML that expresses the content model of BibTeX – the bibliographic system for use with LaTeX. Stylesheets and conversion tools are provided.
now here: https://github.com/plastex/plastex
plasTeX is a Python-based LaTeX document processing framework. It gives DOM-like access to a LaTeX document, as well as the ability to generate mulitple output formats (e.g. HTML, DocBook, tBook, etc.).