This Festschrift volume has been published in honor ofFrank de Boer, on the occasion of his 60th birthday.
Frank S. de Boer is a prominent member of the research community in formalmethods and theoretical computer science. A brief look at his lengthypublication list reveals a broad area of interest and a versatile modusoperandi with: logic and constraint programming; deductive proof systems,soundness, and completeness; semantics, compositionality, and full abstraction;process algebra and decidability; multithreading and actor-based concurrency;agent programming, ontologies, and modal logic; real-time systems, timedautomata, and schedulability; enterprise architectures, choreography, andcoordination; testing and runtime monitoring; and cloud computing and service-levelagreements. For a while, he also liked failures, especially in semantics, andoptimistically concluded with the failure of failures. In fact, Frank has anopportunistic approach to research. Rather than seeing obstacles, he findsopportunities.