[29athrowaway]

The EU asked for the standardization of Microsoft Office file formats, and the "Office Open XML" format (OOXML for short) was created (ECMA-376).

The resulting standard was 6,546 pages long (in comparison, ODF is just 867 pages long), and Microsoft Office was not fully compliant with it, making the entire process a waste of time. 10 years later situation is the same.

It is reasonable to believe that interoperability and standardization were not in the best interest of Microsoft. They have the largest market share and they have not much to win by giving opportunities to competitors.

You can read more here: https://en.wikipedia.org/wiki/Standardization_of_Office_Open...