Ninth international workshop on Principles of software evolution: in conjunction with the 6th ESEC/FSE joint meeting

IWPSE 2007 - Fresh blood for Software Evolution Bits of History. Greetings and welcome to IWPSE 2007, the 9th International Workshop on Principles of Software Evolution! IWPSE 2007 is held in conjunction with the joint meeting of the European Software Engineering Conference (ESEC) and the ACM SIGSOFT Symposium on the Foundations of Software Engineering (FSE). The IWPSE series started in 1998, in Kyoto, and since then continued being held annually over Asia, Europe, and the USA. To provide a broader perspective on software evolution, IWPSE has always been co-located with major international conferences, such as ICSE, ESEC/FSE and RE. Since the first edition, IWPSE has acquired momentum and it is now a truly international forum. This year, IWPSE is held for the first time in Eastern Europe, in the beautiful location of Dubrovnik, Croatia. As the message title implies, this past few years have seen a renewed interest in the topic of software evolution. This is tangible by the number of young and energetic researchers who have joined the research community by opening up new directions, such as the mining of software repositories, which ultimately has given a great impetus to the research field as a whole. This is also attested by the number of sibling venues of IWPSE, such as MSR (the International Workshop on Mining Software Repositories) and EVOL (the ERCIM Symposium on Software Evolution). Technical Program. As always, the technical papers represent the core of the workshop program. This year there were 33 technical paper submissions. After rigorous review of each paper by at least three international reviewers, the program committee selected 9 full papers, 8 short papers, and 3 demo papers for presentation at the workshop and inclusion in the proceedings. We were very pleased with the high quality of paper submissions. Also, we are more than pleased that IWPSE features a provocative keynote address by a leading researcher in the area, prof. Giuliano Antoniol, the Canada Research Chair Tier I in Software Change and Evolution of the Ecole Polytechnique de Montreal.