4 Feb
2010
4 Feb
'10
1:05 p.m.
http://en.wikipedia.org/wiki/Office_Open_XML#cite_note-ODFA_communityone-44
Read the last part, it talks about the Open Office XML guidelines by ISO, which haven't been completely implemented in MS Office 2007. Open Office supports it since version 3.
The bad news is that they have termed it as .docx, .pptx etc extensions. .odf does comply with the Open Office XML guidelines. Read the wiki page and see references in the page for more details.