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 established in 1998 by combining a number of existing and new conf- ences. This year it comprised ?ve conferences (CC, ESOP, FASE, FOSSACS, TACAS), 17 satellite workshops (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 received 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 - velopment process, including speci?cation, design, implementation, analysis and improvement. The languages, methodologies and tools which support these - tivities 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 s- tems,andtheemphasisonsoftwareisnotintendedtobeexclusive.

This book constitutes the thoroughly refereed post-workshop proceedings of the 15th International Workshop on Algebraic Development Techniques, WADT 2001, held jointly with the General Workshop of the ESPRIT Working Group CoFI in Genova, Italy, in April 2001.The book presents 16 papers selected from 32 workshop presentations. Among the topics addressed are formal specification, specification languages, term rewriting, and proof systems.