This book constitutes the refereed proceedings of the 4th European Conference on Model Driven Architecture - Foundations and Applications, ECMDA-FA 2008, held in Berlin, Germany, in June 2008. The 31 revised full papers presented - 21 research papers and 10 industry papers - were carefully reviewed and selected from 87 submissions. The papers address all current issues of model-driven architecture, i.e. model management, executable models, concrete syntaxes, aspects, and concerns, validation and testing, model-based systems engineering, model-driven development and service-oriented architectures, and the application of model-driven development. The papers are organized in topical sections on model management, executable models, concrete syntaxes, aspects and concerns, validation and testing, model-based systems engineering, model-driven development and service-oriented architectures, as well as surveys on applying model-driven development.