ETAPS 2010 was the 13th instance of the European Joint Conferences on T- oryand Practiceof Software. ETAPS is anannual federatedconference that was establishedin1998bycombininganumberofexistingandnewconferences. This yearitcomprisedtheusual'vesisterconferences(CC, ESOP, FASE, FOSSACS, TACAS), 19 satellite workshops (ACCAT, ARSPA-WITS, Bytecode, CMCS, COCV, DCC, DICE, FBTC, FESCA, FOSS-AMA, GaLoP, GT-VMT, LDTA, MBT, PLACES, QAPL, SafeCert, WGT, and WRLA) and seven invited l- tures (excluding those that were speci'c to the satellite events). The ?ve main conferences this year received 497 submissions (including 31 tool demonstration papers), 130 of which were accepted (10 tool demos), giving an overall acc- tance rate of 26%, with most of the conferences at around 24%. Congratulations thereforetoalltheauthorswhomadeittothe'nalprogramme Ihopethatmost 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 to make of 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, withaninclinationtowardtheorywithapracticalmotivationonthe 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. ETAPS is a confederation in which each event retains its own identity, with a separate Programme Committee and proceedings.