The New Microsoft Office XML File Formats

In the 2007 Office release, Word, Excel, and PowerPoint now use the Microsoft Office Open XML Formats, which means that their default file formats are based on XML. The XML file format provides a number of benefits: It provides better security for your files, reduces the chance of file corruption, reduces file size, and facilitates data sharing across data storage and retrieval systems.

Network administrators will like the small file size and reduced chance of corruption. Software developers and programmers will take advantage of the XML file format to integrate 2007 Office release applications with other business applications, even applications that aren’t published by Microsoft. Any application that supports XML can access and work with data in the new Microsoft Office file format.

If you are interested in reading more about the structure and architecture of the Office Open XML Formats, see the article at http://msdn2.micro5oft.com/en-u5/library/m5406049.aspx.

For most users of Microsoft Office, however, the change in file format will be noticeable mainly in the names of your files. For documents, spreadsheets, and presentations, the default file format now has an “x” on the end of the file name extension (.docx, .xlsx, and .pptx), which indicates XML. If you save a file as a template, the file is saved with the former template extension with an “x” on the end: .xltx in Excel, for example. If a file you are working on contains a macro or Visual Basic code, you have to save it using the new macro-enabled file format. For a Word document, that means you save it as a .docm file (or a .dotm file for a Word template).

If you open a file in Word 2007, for example, that was created in a previous version of Word, you will be asked if you want to convert it to the new format. If you say yes, the document will be saved in the new XML format. If you choose not to convert the file, it will retain its original format. You can open and modify it in the 2007 Office system, but some features of the 2007 Office release won’t be available.

If you are using an earlier version of Microsoft Office and you receive a file that was created in the 2007 Office release, you need to download a converter in order to read and edit the 2007 Office system file. You can download a converter at www.microsoft.com.

Note 

Another XML-related file format that’s part of the 2007 Office system is the XML Paper Specification (XPS) Document format, which is a paginated representation of electronic paper, similar to the widely used Portable Document Format (PDF). The XPS Document format lets you create, share, print, and archive paginated documents without any additional tools. You can open an XPS document in your Web browser.