Invited Talks -- Model Checking for Nominal Calculi -- Mathematical Models of Computational and Combinatorial Structures -- Rule Formats and Bisimulation -- Congruence for Structural Congruences -- Probabilistic Congruence for Semistochastic Generative Processes -- Bisimulation on Speed: A Unified Approach -- Probabilistic Models -- Branching Cells as Local States for Event Structures and Nets: Probabilistic Applications -- Axiomatizations for Probabilistic Finite-State Behaviors -- Stochastic Transition Systems for Continuous State Spaces and Non-determinism -- Model Checking Durational Probabilistic Systems -- Algebraic Models -- Free-Algebra Models for the ?-Calculus -- A Unifying Model of Variables and Names -- A Category of Higher-Dimensional Automata -- Games and Automata -- Third-Order Idealized Algol with Iteration Is Decidable -- Fault Diagnosis Using Timed Automata -- Optimal Conditional Reachability for Multi-priced Timed Automata -- Alternating Timed Automata -- Language Analysis -- Full Abstraction for Polymorphic Pi-Calculus -- Foundations of Web Transactions -- Bridging Language-Based and Process Calculi Security -- History-Based Access Control with Local Policies -- Partial Order Models -- Composition and Decomposition in True-Concurrency -- Component Refinement and CSC Solving for STG Decomposition -- The Complexity of Live Sequence Charts -- Logics -- A Simpler Proof Theory for Nominal Logic -- From Separation Logic to First-Order Logic -- Justifying Algorithms for ??-Conversion -- On Decidability Within the Arithmetic of Addition and Divisibility -- Coalgebraic Modal Logics -- Expressivity of Coalgebraic Modal Logic: The Limits and Beyond -- Duality for Logics of Transition Systems -- Computational Models -- Confluence of Right Ground Term Rewriting Systems Is Decidable -- Safety Is not a Restriction at Level 2 for String Languages -- A Computational Model for Multi-variable Differential Calculus.ETAPS 2005 was the eighth instance of the European Joint Conferences on Theory and Practice of Software. ETAPS is an annual federated conference that was est- lished in 1998 by combining a number of existing and new conferences. This year it comprised ?ve conferences (CC, ESOP, FASE, FOSSACS, TACAS), 17 satellite wo- shops (AVIS, BYTECODE, CEES, CLASE, CMSB, COCV, FAC, FESCA, FINCO, GCW-DSE, GLPL, LDTA, QAPL, SC, SLAP, TGC, UITP), seven invited lectures (not including those that were speci?c to the satellite events), and several tutorials. We - ceived over 550 submissions to the ?ve conferences this year, giving acceptance rates below 30% for each one. Congratulations to all the authors who made it to the ?nal program! I hope that most of the other authors still found a way of participating in this exciting event and I hope you will continue submitting. The events that comprise ETAPS address various aspects of the system devel- ment process, including speci?cation, design, implementation, analysis and impro- ment. The languages, methodologies and tools which support these activities are all well within its scope. Di?erent blends of theory and practice are represented, with an inclination towards theory with a practical motivation on the one hand and soundly based practice on the other. Many of the issues involved in software design apply to systems in general, including hardware systems, and the emphasis on software is not intended to be exclusive.