This Festschrift is dedicated to Professor Sjouke Mauw on the occasion of his 65th birthday. Prof. Mauw obtained his PhD from the University of Amsterdam and subsequently held faculty and research positions at Eindhoven University of Technology and at Centrum Wiskunde & Informatica (CWI) in Amsterdam. He has collaborated closely with researchers around the world, including colleagues in Australia, Norway, Singapore, and many other countries. Since 2007, he has served as a full professor at the University of Luxembourg, where he leads the Security and Trust of Software Systems group.A passionate advocate of rigorous formalization, Prof. Mauw specializes in formal methods for information security. He laid the mathematical foundations for attack trees, a practical and widely used security assessment framework, and he contributed extensively to the development of theory and tools for the specification and automated verification of security protocols.Many members of Sjouke Mauw's scientific family have contributed to this volume to honor a distinguished advisor, exceptional mentor, and outstanding educator.