Using C# to read Excel 2003 in XML format <p>I am using Excel 2003. I see that I have the ability to save files in XML format as well as XLSX 2007 format. What this functionality provided by installing something extra like a Comparability Pack or is this base Excel 2003 functionality?</p> <p>The documentation that I see for Excel and XML refers to Open XML and most of what I see is in regards to Office 2007 or greater.</p> <p>Can I use "Open XML" to read the Xml format document that I saved in 2003? Is the XML format that I save it in really the same as the format that is used in office 2007? </p> <p>From this <a href="http://www.microsoft.com/en-us/download/details.aspx?id=5124" rel="nofollow">MS Site</a>:</p> <p>Open XML is an open ECMA 376 standard and is also approved as the ISO/IEC 29500 standard that defines a set of XML schemas for representing spreadsheets, charts, presentations, and word processing documents. Microsoft Office Word 2007, Excel 2007, and PowerPoint 2007 all use Open XML as the default file format. </p> <p>Does this mean that this library can be used to read an Excel 2003 file that I saved as XML? The presumption here is that the XML format used is really 2007 level due to the incompatibility pack.</p>