This Festschrift, dedicated to Reiner Hähnle on the occasion of his 60th birthday, contains papers written by many of his closest collaborators.After positions at Karlsruhe Institute of Technology and Chalmers University of Technology, since 2011 Reiner has been the chaired professor of Software Engineering at Technische Universität Darmstadt, where his team focuses on the formal verification of object-oriented software, the formal modeling and specification of highly adaptive software systems, and formal modeling and analysis in domains such as biological systems and railroad operations. His work is characterized by achievements in theory and in practical implementations, significant collaborations include the KeY project and the development of the ABS language. He has served as chair and editor of important related academic conferences, and coauthored almost 200 academic publications.The contributions in this volume reflect Reiner's main research focus: formal methods, in particular applied to software verification.