This book constitutes the refereed proceedings of the 9th International Software Product Line Conference, SPLC 2005, held in Rennes, France in September 2005, emanating from the merger of the former events SPLC (Software Product Line Conference started 2000 in the USA) and PFE (Product Family Engineering started 1996 in Europe).

The 17 revised full technical papers presented together with 3 short research papers and 2 keynote talks were carefully reviewed and selected for inclusion in the book. The papers are organized in topical sections on keynotes, feature modelling, re-engineering, short papers, strategies, panels, validation, scoping and architecture, and product derivation.