Euro-Office: sovereign in name only, or in reality too?

The announcement of the Euro-Office is welcome news. The coalition is credible, the governance is sound and the timing is perfect. Europe needs office software, and we are delighted to see such significant players allocating resources to make it happen.
However, we have a question. It is not meant to be hostile, but it is the only question that matters.

What is the native document format of Euro-Office?

https://blog.documentfoundation.org/blog/2026/04/01/euro-office/