I can see clearly now: Clairvoyant Assertions for Deadlock Checking -- When COSTA met KeY: Verified Cost Bounds -- Lifelong Learning of Reactive Systems in Practice -- A Case Study in Information Flow Re nement for Low Level Systems -- Re-CorC-ing KeY: Correct-by-Construction Software Development based on KeY -- Specifying the boundary between unverified and verified code -- Programming legal contracts - a beginners guide to Stipula -- Towards a Modular and Variability-aware Aerodynamic Simulator -- Reasoning about Active Objects: A Sound and Complete Assertional Proof Method -- Improving Automatic Complexity Analysis of Integer Programs -- Alice in Wineland: A Fairy Tale with Contracts -- Teaching Design by Contract using Snap -- On the Notion of Naturalness in Formal Modeling -- The Karlsruhe Java Verification Suite -- Further Lessons from the JML Project -- Inference in MaxSAT and MinSAT -- Implications of Deductive Verification on Research Quality -- Computing in Lukasiewicz logic and AF-algebras.-Speaking about Wine: Another Case Study in Bridging the Gap between Formal and Informal Knowledge -- Software & System Verification with KIV -- A Note on Idleness Detection of Actor Systems -- Symbolic Execution: Foundations, Techniques, Applications, and Future Perspectives -- Locally Abstract Globally Concrete Semantics of Time and Resource Aware Active Objects -- Transparent Treatment of for-Loops in Proofs. .

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.