In the short space of about a decade, Commercial-Off-the-Shelf (COTS) software has evolved through being a relatively minor aspect of software development; a t- management-endorsedsilverbulletsolutionforsoftwaredevelopment;adisruptivete- nology requiring people and organizations to extensively rethink their approaches to software development; to an increasingly well-understood software phenomenon for which effective solutions are being developed. Part of this understanding has been to recognize that different COTS application sectors can be at different stages of this evolution. Some sectors are just beginning to become COTS-intensive. Some have evolved COTS solutions that are very well matched to their problem domain. Others, including most large-scale applications, still involve their developers in rethinking how to adapt their traditional software architectures, processes, management practices, and personnel skills to accommodate economically attractive but complex combinations of powerful but incompletely compatible and independently evolving COTS products. The series of International Conferences on COTS-Based Software Systems (ICCBSS) has been established as a continuing forum for bringing together CBSS developers, s- pliers, and researchers to summarize and discuss progress toward understanding and resolving CBSS problems. This year's conference theme, "Matching Solutions to P- blems,"re?ectsthisobjective.Wehavebeenfortunatetohavethreeoutstandingkeynote speakers, David Carr, Tricia Oberndorf, and Douglas Schmidt, who have contributed signi?cantly both in analyzing CBSS problems and developing better CBSS solutions. The contributed papers and summaries of workshops, panels, and tutorials in theseProceedingsgiveagoodunderstandingofthenatureanddirectionsofevolutionofCBSS problems and solutions.As has been my experience with previous ICCBSS Proceedings volumes, I believe that you will ?nd lasting value in the content of the Proceedings.