It is a great pleasure to me to have the opportunity of writing a preface to Klaus Kilberth's book on JSP. He has been an enthusiastic and expert practitioner of JSP for several years, and he is also an experienced teacher of the method. So I was expecting his book to contain a careful exposition of JSP, including some of its newer aspects, and that expectation has been amply fulfilled. It is also good to see that he has included many exercises, along with their solutions, and that he has maintained the excellent JSP tradition of explanation by story-telling: in future I shall drink my German wine with increased pleasure, thinking of the admirable career of Gustav and how useful his instinctive understanding of process communication proved to be in the wine trade. I hope that you, the reader, will enjoy this book, and that you will benefit from its insights into the task of composing correct programs.