Standardization of Office Open XML

The Office Open XML file formats, also known as OOXML, were standardised between December 2006 and November 2008, first by the Ecma International consortium (where they became ECMA-376), and subsequently, after a contentious standardization process, by the ISO/IEC's Joint Technical Committee 1 (where they became ISO/IEC 29500:2008). == Standardization within Ecma International == More than a year after being asked by the European Union to standardize their Office 2003 XML formats, Microsoft submitted 2,000 pages of documentation for a new file format to the Ecma International consortium for it to be made into an open standard.

Source: Wikipedia — Standardization of Office Open XML (CC BY-SA 4.0)