OOXML (Office Open XML)

Office Open XML (commonly referred to as OOXML or OpenXML) is an XML-based file format specification for electronic documents such as spreadsheets, charts, presentations and word processing documents.

Microsoft originally developed the specification as a successor to its binary Microsoft Office file formats and it was handed over to Ecma International to be developed by the Ecma International Technical Committee TC45, as the Ecma 376 standard, which was published in December 2006.

Controversially, the specification is currently undergoing fast-track standardization within ISO/IEC as DIS 29500 (Draft International Standard 29500), but the draft text has failed (as of the September 2007 ballot) to reach sufficient approval from ISO/IEC national body members to be accepted as a standard. An ballot resolution process will allow for the text to be amended and a final decision to be reached on its acceptability for standardization.