This book constitutes the refereed proceedings of the 15th International Conference on Software Architecture, ECSA 2021, held in Sweden, in September 2021. Due to the COVID-19 pandemic, the conference was held virtually. For the Research Track, 11 full papers, presented together with 5 short papers, were carefully reviewed and selected from 58 submissions. The papers are organized in topical sections as follows: architectures for reconfigurable and self-adaptive systems; machine learning for software architecture; architectural knowledge, decisions, and rationale; architecting for quality attributes; architecture-centric source code analysis; and experiences and learnings from industrial case studies.

Research in software composition investigates models and techniques to build systems from prede?ned, pretested, reusable components instead of building them from scratch. In recent years, this idea has largely been adopted by - dustry. In the shape of service-oriented architecture, software composition has becomeanin?uentialdesignparadigm,especiallyforthe (re-)organizationofthe IT infrastructure of organizations.On the technical level, the standardization of Web services and other composition technologies has further matured. Current research in software composition aims at (further) developing c- position models and techniques. The aspect-oriented programming and design paradigm, for instance, has gained interest in the research community as a c- position (support) model. Other current research questions concern the sp- i?cation of component contracts, in particular making explicit its observable behavior, and methods of correct components composition. The International Symposium on Software Composition provides a premier forum for discussing these kinds of research questions and presenting original research results. This LNCS volume contains the proceedings of the 5th International S- posium on Software Composition, which was held as a satellite event of the European Joint Conferences on Theory and Practice of Software (ETAPS) in Vienna, Austria, March, 25-26 2006. The symposium started with a keynote on “Semantically Enabled Service-Oriented Architectures” given by Dieter Fensel, DirectoroftheDigitalResearchInstitute.Themainprogramconsistedofpres- tations of research papers on software compositions. These proceedings contain the revised versions of the papers presented at SC 2006.

This book constitutes the refereed proceedings of the 15th International Conference on Software Architecture, ECSA 2021, held in Sweden, in September 2021. Due to the COVID-19 pandemic, the conference was held virtually. For the Research Track, 11 full papers, presented together with 5 short papers, were carefully reviewed and selected from 58 submissions. The papers are organized in topical sections as follows: architectures for reconfigurable and self-adaptive systems; machine learning for software architecture; architectural knowledge, decisions, and rationale; architecting for quality attributes; architecture-centric source code analysis; and experiences and learnings from industrial case studies.

Research in software composition investigates models and techniques to build systems from prede?ned, pretested, reusable components instead of building them from scratch. In recent years, this idea has largely been adopted by - dustry. In the shape of service-oriented architecture, software composition has becomeanin?uentialdesignparadigm,especiallyforthe (re-)organizationofthe IT infrastructure of organizations.On the technical level, the standardization of Web services and other composition technologies has further matured. Current research in software composition aims at (further) developing c- position models and techniques. The aspect-oriented programming and design paradigm, for instance, has gained interest in the research community as a c- position (support) model. Other current research questions concern the sp- i?cation of component contracts, in particular making explicit its observable behavior, and methods of correct components composition. The International Symposium on Software Composition provides a premier forum for discussing these kinds of research questions and presenting original research results. This LNCS volume contains the proceedings of the 5th International S- posium on Software Composition, which was held as a satellite event of the European Joint Conferences on Theory and Practice of Software (ETAPS) in Vienna, Austria, March, 25-26 2006. The symposium started with a keynote on “Semantically Enabled Service-Oriented Architectures” given by Dieter Fensel, DirectoroftheDigitalResearchInstitute.Themainprogramconsistedofpres- tations of research papers on software compositions. These proceedings contain the revised versions of the papers presented at SC 2006.