Two Office Open XML file types in save? [closed]

edit

Office Open XML is Microsoft developed standard that no product really support it fully - not even Microsoft's one. Microsoft Office XML format was introduced in Microsoft Office 2007.

Read more:

http://en.wikipedia.org/wiki/Office_Open_XML

http://en.wikipedia.org/wiki/Microsoft_Office_XML_formats

For my local documents I always use ODF file format, because this is default LibreOffice format. For any documents that I am exchanging with Microsoft Office users I always save in "Microsoft Word/Excel/... 97/2000/XP/2003 (.doc)" format. So I am sure all users with older and newer Microsoft Offices can open this document.

If you are sure that users use Microsoft Office 2007 or newer then you can also save in Microsoft Office XML format. But I would avoid using "Office Open XML" at present time, because of lack of support. Microsoft Office 2010 can only open this file types, but can't save in it - you see if Microsoft does not support save into this kind of format, I would avoid using it at all.