Microsoft office: via XML

Microsoft has confirmed that it will move to XML-based file formats as the default option for its most popular Office applications in the next release of the Office suite, and that it has no intention of adopting the OpenDocument format recently adopted as a standard by Oasis.

The company will begin using Microsoft Office Open XML Formats for its Word, Excel, and PowerPoint applications, with the codename Office 12, which is due for release in the second half of 2006

[ I bet its based on the XBRL they've got going ]