File Formats Improve Application Access, Require Planning

New XML-based file formats are the default for Word, Excel, PowerPoint, and Access in Office 2007. The formats offer smaller file size, better security, and more direct access to Office data by third-party applications, which will strengthen Office as a client for document management. Office 2007 will support existing Office file formats, and older versions will support the new formats with an add-on. To use the new formats, organizations will need to plan Office migrations carefully so that their chosen format is the default for the organization and can be read by all users, including vendors, partners, and contractors.

New Formats for Compression, Security, Applications

Word, Excel, PowerPoint, and Access 2007 all save documents by default as compressed (zipped) packages with document content and formatting in XML. These new XML-based formats resemble the optional XML formats currently supported by Word and Excel 2003.

The new default formats have several advantages:

Smaller file size. XML formats typically produce larger files than binary formats do, but the files compress better. As a result, Office XML files can actually be significantly smaller than the corresponding binary files. (See the chart “File Sizes by Format“.) On the other hand, some files in the new formats will take longer to load because of the overhead of uncompressing and processing XML. Large Excel XML files are particularly slow, so Microsoft has created a new Excel 2007 binary file format intended to enable large workbooks to load more quickly.