ThisvolumecontainstheproceedingsoftheIFIPWG6. 1InternationalWorking Conference on Distributed Applications and Interoperable Systems V held in Athens, Greece, on June 15-17, 2005. The conference program presented the state of the art in research concerning distributed and interoperable systems. The emergence of 4th-generation c- munication systems, the evolution of Internet technologies, the convergence of telecom and datacom, wireless and xed communication systems and appli- tions pave the path for ubiquitous service and application provision. Innovative solutions are required for the development, implementation and operation of distributed applications in complex IT environments full of diversity and h- erogeneity. Today, the emerging wide spectrum of distributed systems - ranging from ambient intelligence to global computing scenarios - lacks systematic - plication development support. Following the evolution of the ?eld, DAIS 2005 focuses on models, technologies and platforms for interoperable, scalable and adaptable distributed applications within all kinds of computing environments. The papers presented at DAIS 2005 cover methodological aspects of building and architecting distributed and interoperable services, interoperability te- nologies, context- and location-based applications, con?gurability of commu- cation services, performance issues, data-integration issues, and Web services. In comparison to earlier events, the submissions showed increased interest towards methodological aspects and large-scale system interoperability. These proceedings contain 16 regular and 5 short papers, which were - lected in a careful, international reviewing process.