Meta bug about single XML document – also known as Flat XML or Uncompressed XML Files. Single OpenDocument XML files are not widely used, they are also unsupported on some office software which claims to support ODF (Microsoft Office applications version 2007 to 2013 do not recognize them). Filename extensions for a single OpenDocument XML documents are not defined in the OpenDocument technical specification, but commonly used are .xml, .fodt, .fods, ... etc.
(cited from https://en.m.wikipedia.org/wiki/OpenDocument_technical_specification)
Is it even possible to save documents into flat XML files? I don't see this as an output filter in a recent Writer nightly.
(In reply to Eyal Rozenberg from comment #1)
> Is it even possible to save documents into flat XML files? I don't see this
> as an output filter in a recent Writer nightly.
File -> Save As..., then choose 'Flat XML ODF Text Document (.fodt)' from the dropdown (the other apps should have similar entries with their corresponding formats).