This book constitutes the revised selected papers of the 9th International Symposium on Formal Aspects of Component Software, FACS 2012, held in Mountain View, CA, USA in September 2012. The 16 full papers presented were carefully reviewed and selected from 40 submissions. They cover topics such as formal models for software components and their interaction; formal aspects of services, service oriented architectures, business processes, and cloud computing; design and verification methods for software components and services; composition and deployment: models, calculi, languages; formal...