Primavera offers XML options compatible with Microsoft Project 2003, 2007 and 2010; MPP for Project 2003; and MPX for older versions of Project. Choose "Microsoft Project" as the file format.

How to Open Microsoft XPS Document Writer Files. XPS is short for XML Paper Specification. It was invented by Microsoft as a replacement for PDF files.

Ecma, the international standards body accepted Microsoft's proposed Open XML File Format submission for standardization.