Does The Document Foundation Support OOXML?
Soon after the release of LibreOffice 3.3, the Steering Committee posted their position on OOXML support in LibreOffice. Some of those that have tested the LibreOffice office suite knows that they can open and save in Microsoft Office formats. So, The Document Foundation supports OOXML then? Well, no, not really.
According to a new foundation wiki page, The Document Foundation does not support OOXML. It states the foundation supports only Open Standards such as the OpenDocument Format (ODF). But if users can read and write to Microsoft Office documents, isn't that OOXML support?
The foundation explains that the formats used in Microsoft Office, called OOXML, are not the same thing as the ISO standard of the same name. In fact, they quip "it is unclear whether anyone is able to implement the ISO standard." But it is unwise not to support any commonly used document format or else risk becoming irrelevant. So, they choose to support these formats for user convenience.
in order to enable users to read and write to documents saved in Microsoft Office formats, LibreOffice has employed patches from Novell which are the result of certain controversial agreements between Novell and Microsoft. If users wish to disable this feature it is possible. One method is to just save in OpenDocument formats, or one can go as far as to deactivate it. The Microsoft Office formats can be deactivated by following this howto, which basically consists of editing LibreOffice .xcd files and removing the word "EXPORT" from a value line.
So, does The Document Foundation support OOXML? The short answer is: No, but they support Microsoft Office formats.