openxmllib is a Python package that processes Open XML documents and renders them in various ways.
Open XML is the office document format supported natively by MS Office 2007, and as import/export format by Apple iWork‘08 and OpenOffice 2.2.
Open XML format is specified by the ECMA-376 standard and now recorded as ISO/IEC standard ISO/IEC 29500.
Some starters about this format are available at Wikipedia page about ECMA-376. Wikipedia has another page that lists the softwares that support this format.