Related question: I'd like to merge a pdf form with xml data on the server side, preferably in PHP but I'm flexible. I have a PDF that I've loaded into Acrobat Pro 9 and using Forms > Manage Form Data > Import Data, I can load xml from an XDP file that was created by initially exporting the form data, making a copy, and changing some of the values. That works flawlessly and populates all of my form fields. Now I nee dto do it programmatically on the server side, save as a new PDF file with these fields pre-filled, and redirect the user (using header(Content-Type: ???); echo $content;) to the new file. I've seen lots of examples using FDF and XFDF but I am guessing these are obsolete/deprecated and I can't get them to work in my current browser/acrobat reader. What is the current "best practice" way of doing server-side merging of xml data with a PDF form?