Book excerpt: This book constitutes the joint refereed post-conference proceedings of 12 workshops held in conjunction with the 11th European Conference on Object-Oriented Programming, ECOOP '97, in Jyvskyl, Finland, in June 1997. The volume presents close to 100 revised selected contributions, including surveys by the respective workshop organizers. The wealth of up-to-date information provided spans the whole spectrum of Object Technologies, from theoretical and foundational issues to applications in a variety of domains.