Today's author: Danny Khen, a program manager who works on both the Excel and Excel Services teams. What is this about? Office 2007 introduced new default file formats – Open XML. Excel, Word and PowerPoint take advantage of them. One of the nicest things about those file formats is that they enable easy manipulation of Office documents without needing the Office applications up and running – by simply modifying XML “parts” within the files. In June 2007 we published an SDK that facilitates this...