This Festschrift, dedicated to Frits W. Vaandrager on the occasion of his 60th birthday, contains papers written by many of his closest collaborators. Frits has been a Professor of Informatics for Technical Applications at Radboud University Nijmegen since 1995, where his research focuses on formal methods, concurrency theory, verification, model checking, and automata learning. The volume contains contributions of colleagues, Ph.D. students, and researchers with whom Frits has collaborated and inspired, reflecting a wide spectrum of scientific interests, and demonstrating successful work at the highest levels of both theory and practice.

This book constitutes the proceedings of the 24th International Conference on Formal Methods and Software Engineering, ICFEM 2023, held in Brisbane, QLD, Australia, during November 21–24, 2023. The 13 full papers presented together with 8 doctoral symposium papers in this volume were carefully reviewed and selected from 34 submissions, the volume also contains one invited paper. The conference focuses on applying formal methods to practical applications and presents papers for research in all areas related to formal engineering methods.

This open access book constitutes the proceedings of the 26th International Conference on Foundations of Software Science and Computational Structures, FOSSACS 2023, which was held during April 22-27, 2023, in Paris, France, as part of the European Joint Conferences on Theory and Practice of Software, ETAPS 2023. The 26 regular papers presented in this volume were carefully reviewed and selected from 85 submissions. They deal with research on theories and methods to support the analysis, integration, synthesis, transformation, and verification of programs and software systems.

This book constitutes the proceedings of the First International Conference on Bridging the Gap between AI and Reality, AISoLA 2023, which took place in Crete, Greece, in October 2023. The papers included in this book focus on the following topics: The nature of AI-based systems; ethical, economic and legal implications of AI-systems in practice; ways to make controlled use of AI via the various kinds of formal methods-based validation techniques; dedicated applications scenarios which may allow certain levels of assistance; and education in times of deep learning.

This book constitutes the refereed proceedings of the 35th IFIP WG 6.1 International Conference on Testing Software and Systems, ICTSS 2023, held in Bergamo, Italy, during September 18-20, 2023. The 13 full papers presented together with 6 short papers and one journal paper were carefully reviewed and selected from 56 submissions. The conference focuses on Test Case Generation; Test Automation and Design; Model Based Testing; and AI and Smart Contracts Testing.