After all its efforts in support of OOXML, Microsoft has decided Office 2007 will handle ODF documents - and will never support the standardised version of its OOXML format, which it fought so hard for.

The announcement surprised everyone yesterday. ODF 1.1 will be supported in a service pack for Office 2007, and the ISO version of Office 2007's native OOXML won't be supported until Office 14, which has not yet got an announced shipping date. Even more surprisingly, users will apparently get the option to set ODF as the default format for their Office installations.

The most likely explanation for such a major change is simply that ODF is the only format that is currently available as an ISO/IEC standard (OOXML is still being finished) and that, after all, is the aim here.

"Why will Microsoft do this after so many years of refusal? Perhaps because the only way it can deliver a product to government customers that meets an ISO/IEC document format standard is by finally taking the plunge, and supporting 'that other format'," says Andy Updegrove.

It's a bit more complicated than that, because Microsoft is actually supporting ODF 1.1, the current native version in packages like OpenOffice, and not DIS 26300, the ISO/IEC standard based on ODF 1.0. But that's the "safe" version that people will be using, it has more features, and it will be the basis of the next ODF-based ISO standard.

If Microsoft really is making the move to keep government bodies happy, ODF 1.1 should do the job nicely (we've run news stories on the differences between versions of ODF and OOXML).

Oh and there's more. Microsoft is also promising native support for PDF.