Microsoft Office XML Formats - Limitations and Differences With Office Open XML

Limitations and Differences With Office Open XML

Besides differences in the schema, there are several other differences between the earlier Office XML schema formats and Office Open XML.

• Whereas the data in Office Open XML documents is stored in multiple parts and compressed in a ZIP file conforming to the Open Packaging Convention, Microsoft Office XML formats are stored as plain single monolithic XML files (making them quite large, compared to OOXML and the Microsoft Office legacy binary formats). Also, embedded items like pictures are stored as binary encoded blocks within the XML. In case of Office Open XML, the header, footer, comments of a document etc. are all stored separately.
• XML Spreadsheet documents cannot store Visual Basic for Applications macros, auditing tracer arrows, chart and other graphic objects, custom views, drawing object layers, outlining, scenarios, shared workbook information and user-defined function categories. In contrast, the newer Office Open XML formats support full document fidelity.
• Poor backward compatibility with the version of Word/Excel prior to the one in which they were introduced. For example, Word 2002 cannot open Word 2003 XML files unless a third-party converter add-in is installed. Microsoft has released a Word 2003 XML Viewer which allows WordProcessingML files saved by Word 2003 to be viewed as HTML from within Internet Explorer. For Office Open XML, Microsoft provides converters for Office 2003, Office XP and Office 2000.
• Office Open XML formats are also defined for PowerPoint 2007, equation editing (Office MathML), vector drawing, charts and text art (DrawingML).