This book presents the thoroughly refereed and revised proceedings of the 15th Monterey Workshop, held in Budapest, Hungary, September 24-26, 2008. The theme of the workshop was Foundations of Computer Software, Future Trends and Techniques for Development. The 13 revised full papers presented at the workshop explore, how the foundations and development techniques of computer software could be adapted to address such a challenge. Material presented in the papers spans the whole software life cycle, starting from specification and analysis, design and the choice of architectures, large scale, real-world software development, code generation and configuration, deployment, and evolution.