Use of a Canonical Hidden-Variable Space in Quantum Mechanics -- Imperfect Information in Logic and Concurrent Games -- Compositional Quantum Logic -- The Algebra of Directed Acyclic Graphs -- Diagrammatic Reasoning for Delay-Insensitive Asynchronous Circuits -- Payoffs, Intensionality and Abstraction in Games -- On the Theory of Composition in Physics -- On the Functor 2 -- Quantum Speedup and Categorical Distributivity -- Unifying Semantics for Concurrent Programming -- Unfixing the Fixpoint: The Theories of the λY -Calculus -- Continuous Domain Theory in Logical Form -- Presheaf Models of Quantum Computation: An Outline -- Nothing Can Be Fixed -- Dialogue Categories and Frobenius Monoids -- Anatomy of a Domain of Continuous Random Variables II -- Towards Nominal Abramsky -- Techniques for Formal Modelling and Analysis of Quantum Systems -- Quantum Field Theory for Legspinners -- Bicompletions of Distance Matrices -- Partial Recursive Functions and Finality -- Breaking the Atom with Samson -- Reasoning about Strategies -- Domain Theory in Topical Form -- Kolmogorov Complexity of Categories.

This Festschrift volume, published in honor of Samson Abramsky, contains contributions written by some of his colleagues, former students, and friends. In celebration of the 60th birthday of Samson Abramsky, a conference was held in Oxford, UK, during May 28-30, 2010. The papers in this volume represent his manifold contributions to semantics, logic, games, and quantum mechanics.