A very interesting analysis of the way that Office 2007 works with saving documents to the supposedly open XML document format by MS:
http://ooxmlisdefectivebydesign.blogspot.com/And as you can see this only scrapes the surface of how this "format" is implemented, yet it has revealed exactly how proprietary it is without even going into a deeply technical realm.
An appropriate cartoon for the occasion, since MSXML seems to be getting more Yes votes than it should...
http://www.noooxml.org/local--files/start/isomeeting.jpg
