This book contains the proceedings of a third workshop on the theme of Software Arc- tecture for Product Families. The first two workshops were organised by the ESPRIT project ARES, and were called Development and Evolution of Software Architectures for Product Families . Proceedings of the first workshop, held in November 1996, were only published electronically at: http: //www.dit.upm.es/ ares/ . Proceedings of the second workshop, held in February 1998, were published as Springer LNCS 1429. The ARES project was finished in February 1999. Several partners continued - operation in a larger...