For an overview of the new XML file formats in the 2007 Office system, see File format reference for the 2007 Office system. For a detailed, developer-oriented reference, see 2007 Microsoft Office System on MSDN (http://go.microsoft.com/fwlink/?LinkId=76286).

The change in file formats is a direct result of customer feedback. External MVPs, developers, and IT administrators provided crucial feedback about their requirements, as follows:

• Provide a file format based on open standards.

• Make files easier to manipulate programmatically.

• Make files easier to search.

• Help make files more secure.

• Provide a way to identify whether a file has been tampered with or contains a virus.

• Make files less sensitive to corruption.

• Find a way to address data bloat.

The design and development teams for 2007 Office system did the following:

• Worked closely with users to discuss their needs and gather requirements for the new file format.

• Announced the file format early in the development cycle.

• Supplied information about the upcoming changes, and provided more detailed documentation and support.

• Provided tools to help assess the impact of the file format change on IT environments.

• Created as seamless a transition as possible for users, both in migrating to the new file format and in collaborating with previous versions of Office.

There are several ways that people using different versions of Office can collaborate. Users need to share files without encountering any issues with formatting, styles, printing, or feature incompatibility. Users should be able open files received from others, make changes, and send the updated file back regardless of the version of Office they are using.

A set of tools is available for Office 2000, Office XP, and Office 2003 to allow these versions to recognize, open, modify, and save files that are in the new XML format. For more information about the updates and converters available for previous versions of Office, see Collaborating with previous versions of Office and other programs.

In addition, the 2007 Office system minimizes file compatibility issues by including the following features:

• The ability to save files in 2007 Office system to the previous file formats.

• The ability for features that are only available in the 2007 Office system to successfully roundtrip, or go from the 2007 Office system to a previous version of Office, and then back again.

• Group Policy settings that allow you to control the default file formats for each Office application.

• Compatibility mode, which disables features that are not compatible with previous versions.

• A compatibility checker, which informs the user about any features in the document that might not be compatible with previous versions of Office.

Yes. Updates and file converters for Office 2000, Office XP, and Office 2003 are available at Microsoft Office Compatibility Pack for Word, Excel, and PowerPoint 2007 File Formats (http://go.microsoft.com/fwlink?LinkID=77512).

Also, applications in the 2007 Office system can save files to the previous file format. Feature incompatibility will still be an issue, however. Where possible, features available in the 2007 Office system will be emulated in previous versions, but if the previous version of Office cannot support a new feature, the new feature will be ignored.

So that you can identify files in the new XML file format, files have different file extensions than their counterparts in previous versions of Office. Files that are saved in the 2007 Office system to the older format use the old extensions.

Files created in the new XML formats are up to 75 percent smaller than those in previous versions of Office. For example, a 100-KB file with no graphics that is created by using Office 2003 is reduced to about 25 KB in size when saved in the 2007 Office system. These files take up less server space and consume less network bandwidth.

This topic is included in the following downloadable book for easier reading and printing:

• Planning and architecture for the 2007 Office release

See the full list of available books at Office Resource Kit information.

Concepts