ETAPS 2009 was the 12th instance of the European Joint Conferences on T- oryand Practiceof Software. ETAPS is anannual federatedconference that was establishedin1998bycombininganumberofexistingandnewconferences. 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, and WING), fourtutorials, andseveninvitedlectures(excludingthosethatweres- ci?c to the satellite events). The ?ve main conferences...