: Natively supports .doc , .xls , and .ppt formats. To open modern .docx or .xlsx files, you must install the Microsoft Office 2007 Compatibility Pack, which can be difficult to integrate into a portable build. Significant Risks & Limitations Support has ended for Office 2003 - Microsoft Support
Office 2003 became the "golden version" for portability for several unique reasons: Microsoft Office 2003 - Portable Version full version