In this book we develop powerful techniques based on formal methods for the verification of correctness, consistency and safety properties related to dynamic reconfiguration and communication in complex distributed systems. In particular, static analysis techniques based on types and type systems are an adequate methodology considering their success in guaranteeing not only basic safety properties, but also more sophisticated ones like deadlock or lock freedom in concurrent settings.The main contributions of this book are twofold. i) We design a type system for a concurrent object-oriented calculus to statically ensure consistency of dynamic reconfigurations. ii) We define an encoding of the session pi-calculus, which models communication in distributed systems, into the standard typed pi-calculus. We use this encoding to derive properties like type safety and progress in the session pi-calculus by exploiting the corresponding properties in the standard typed pi-calculus.

This book constitutes the refereed proceedings of the 23rd IFIP WG 6.1 International Conference on Coordination Models and Language, COORDINATION 2021, held in Valletta, Malta, in June 2021, as part of the 16th International Federated Conference on Distributed Computing Techniques, DisCoTec 2021.The 15 regular papers, 2 short papers, and 1 tutorial paper presented in this book were carefully reviewed and selected from 31 submissions. COORDINATION provides a well-established forum for the growing community of researchers interested in coordination models and languages, architectures, verification and implementation techniques necessary to cope with the complexity induced by the demands of today's software development. The tool papers describe experience reports, technological artefacts, and innovative prototypes, as well as educational tools in the scope of the research topics of the conference. Due to the Corona pandemic this event was held virtually.