Microsoft has made sure to make a range of XPS-related resources available via MSDN, its portal for the developer community. If you are a Print Driver developer using the XPS Filter Pipeline, you can now use unmanaged XPS functions that were previously only available as .NET managed code. Because these functions were originally written for .NET, they could not be called from a Print driver until now. These XPS functions will enable driver developers to modify XPS documents in greater detail when they are in the filter pipeline. This will make it possible to make custom changes to the documents before they get to the printer, revealed.  In addition, this API allows you to have access to the document metadata and content. For more information, see the XPS Document Programming Guide and Reference at MSDN .