[StJacques]

". . . They have enabled their operating systems to handle Office XML better because they are the only ones with full access to the DTD. . . ."

DTDs are not used in MS Office. They employ XML Schemas. And anyone is capable of writing a new XML Schema and DOM manipulation code to format and manipulate information in MS Office XML documents. I have done so myself. Did I create the same functionality as that which is available on the Windows operating systems? No. But was I able to use the information? You bet. And our clients loved it.

". . . Which they immediately made proprietary so that others couldn't operate with Windows machines as well as Windows machines could. Face it, Microsoft has a history of format lock-in. Meanwhile, by their very nature, open source products have fully open and accessible formats and protocols. . . ."

First; it's not the XML which is proprietary in the case of MS Office Documents, it's the operating system components that use the XML. There is not one format for any XML document anywhere on planet earth that is proprietary.

Second; all of the information created at user-level in MS Office XML Documents for Word, Excel, and Outlook is accessible outside of the Windows operating systems. It is the full capabilities for manipulation and use of that information that is restricted to Microsoft's proprietary technologies. That still establishes cross-platform interoperablility provided that a developer making use of the MS Office XML Document knows how to extract the information. That doesn't mean that he or she can manipulate the information to the same extent one can using the Windows operating system.

[rit]

Another researcher also claims Microsoft's Office file formats are not open. See Analyst: MS Office Formats Not Open.

[antiRepublicrat]

It is the full capabilities for manipulation and use of that information that is restricted to Microsoft's proprietary technologies.

What good is that information if full use of it is proprietary?