This Festschrift is dedicated to Joost-Pieter Katoen in recognition of his outstanding research, teaching, and organizational successes. Joost-Pieter received his Master's and later his Ph.D. from the University of Twente, and his Professional Doctorate in Engineering from Eindhoven University of Technology. He had research positions at the University of Erlangen-Nuremberg and Philips Research, and visiting professorships in France, Australia, and the UK. Since 2004 he has been a professor at RWTH Aachen University and is part-time associated with the University of Twente. Joost-Pieter's main areas of research are formal methods, computer-aided verification, concurrency theory, probabilistic computation, and semantics. Among many recognitions for this work, he is an ACM Fellow; he was elected as a member of the Academia Europaea, the Royal Holland Society of Science and Humanities, the North Rhine-Westphalian Academy of Science, Humanities and the Arts, and the Leopoldina, the German National Academy of Sciences; he received an honorary doctorate from Aalborg University. He was awarded an ERC Advanced Grant; he has won best paper, distinguished paper, or test-of-time awards at key conferences such as ETAPS, IEEE SRDS, POPL, CONCUR, and LOPSTR; and he has given keynotes at dozens of major events. He has chaired the Steering Committee of the European Joint Conferences on Theory and Practice of Software (ETAPS) and the TACAS conference; he has been Program Chair, General Chair, or Program Committee member of hundreds of major conferences and workshops, and a board member of key journals; he has served on research boards (such as the EPSRC), doctoral committees, school and university committees, and IFIP working groups; and he coauthored Principles of Model Checking, a highly influential textbook. Throughout his career Joost-Pieter has been a remarkably successful teacher and mentor, supervising students and hosting postdoctoral researchers, many of whom have won awards for their research and advanced to senior positions, and he has collaborated in research and publications with a wide range of scientists. These successes are reflected in the papers contributed to this volume.