This book constitutes the thoroughly refereed papers presented at five international workshops held in conjunction with the 5th International Conference on Service-Oriented Computing, ICSOC 2007, in Vienna, Austria, in September 2007. The five workshops were selected out of eight submissions. The volume contains papers presented at the First International Workshop on Web APIs and Services Mashups (Mashups 2007), the Workshop on Non-Functional Properties and Service Level Agreements in Service-Oriented Computing (NFPSLA-SOC 2007), the 2nd International Workshop on Business-Oriented Aspects Concerning Semantics and Methodologies in Service-Oriented Computing (SeMSoC 2007), the First International Workshop on Telecom Service-Oriented Architectures (TSOA 2007) and the Third International Workshop on Engineering Service-Oriented Applications (WESOA 2007). The papers offer a wide range of hot topics in service-oriented computing: development of mashups; management of non-functional properties and service level agreements; engineering approaches; semantic methodologies; and telecom services and service architectures.