Programming Languages and Systems: 18th European Symposium on Programming, ESOP 2009, Held as Part of the Joint European Conferences on Theory and . (Lecture Notes in Computer Science, 5502)

ETAPS 2009 was the 12th instance of the European Joint Conferences on T- ory 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), 22 satellite workshops (ACCAT, ARSPA-WITS, Bytecode, COCV, COMPASS, FESCA, FInCo, FORMED, GaLoP,GT-VMT, HFL, LDTA, MBT, MLQA, OpenCert, PLACES, QAPL, RC, SafeCert, TAASN, TERMGRAPH, andWING), four tutorials,andseveninvitedlectures (excludingthose thatwere speci?c to the satellite events). The ?ve main conferences received 532 subm- sions (including 30 tool demonstration papers), 141 of which were accepted (10 tool demos), giving an overall acceptance rate of about 26%, with most of the conferences at around 25%. Congratulations therefore to all the authors who made it to the ?nal programme! I hope that most of the other authors will still have found a way of participating in this exciting event, and that you will all continue submitting to ETAPS and contributing towards making it the best conference on software science and engineering. 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.