Erik Siegel is a content engineer and XML specialist who runs Xatapult consultancy in the Netherlands. He specializes in content design and conversions, XML Schemas and transformations, eXist and XProc applications, and XML-related training. Since 2017, he has been part of the XProc 3.0 editorial team.
Erik has written the must-have programmer's guide to XProc 3.0. Not only is it an excellent reference to all of XProc's features and steps, it includes examples and recipes that you can put to use immediately. Highly recommended! -- Norman Tovey-Walsh, developer of XML Calabash Erik Siegel's XProc 3.0 Programmer Reference is the ideal guide for learning XProc 3.0. The basic concepts are carefully explained and illustrated by many examples. Additionally there is a later chapter with recipes which will prove to be very helpful for everyday work. And it is fun to read! -- Achim Berndzen, developer of MorganaXProc Erik's book is the best text about XProc that I have come across. Easy to read, it helps you to understand and appreciate XProc concepts. And its description of the new 3.0 facilities makes you eager to use them. -- Pieter Masereeuw, self-employed XML specialist