Proceedings of the 19th ACM SIGSOFT symposium on the foundations of software engineering and 13th European software engineering conference : ESEC-FSE'11, ASAS'11, IWPSE-EVOL'11, PASTE'11 and WoSQ'11, 8th joint meeting, Szeged, Hungary, September 5-9, 2011. (ACM - Association for Computing Machinery, 2011)