Learn More. The first draft of the Office Open XML file format specification, which Microsoft submitted to standards body Ecma International in November 2005, has been published.

Microsoft’s bid to have its Open XML file format approved as an ISO standard took another step forward Monday when that organization put the measure on a voting ballot sent to its member countries.

In some cases, Office 2008 for Mac couldn't identify which version of the XML format was being used, and therefore would not open the file.