The 2007 Microsoft Office system will use the Open XML file formats as their default format, and Microsoft has started to publish white papers, code samples, and other Open XML content for developers.
The following is an overview of some of the Open XML information that is currently available on MSDN, including general XML resources, information about Open XML development, and documentation of Microsoft schemas that can be used with Open XML due to its flexible support for custom schemas. Watch for more of this type of content in the months ahead.
Walkthrough: Word 2007 XML Format. This article by Erika Ehrli covers the basics of the packaging convention and then gets into the details of how Word uses Open XML: which parts are included and how they're related, how the custom XML data store works, and an example of how to create a typical WordprocessingML document.
2007 Office System: XML Schema Reference. Documentation in CHM and HTML format for the schemas used in the 2007 Microsoft Office system, including schemas that are not part of the Open XML specification (as used in Outlook 2007, OneNote 2007, and Visio 2007).
2007 Office System Sample: Open XML File Format Code Snippets for Visual Studio 2005. These are the snippets that were covered on OpenXmlDeveloper.org here.
Microsoft XML Team's WebLog. Microsoft's XML team covers a variety of XML topics.
Introducing the Office (2007) Open XML File Formats. Frank Rice reviews some of the most common Open XML development scenarios, and describes the benefits of Open XML in plain English. He also covers the various file formats supported by Office, how to implement Office's CustomUI functionality, and related topics.
Microsoft Office Open XML Formats Frequently Asked Questions. Answers to dozens of questions about Open XML and how it has been implemented in the 2007 Microsoft Office system.
XML in Office Developer Portal. A portal that aggregates many online resources for developers working with XML in Office, including both Open XML resources and other types of XML resources.