As software systems become increasingly ubiquitous, issues of dependability become ever more crucial. Given that solutions to these issues must be considered from the very beginning of the design process, it is reasonable that dependability and security are addressed at the architectural level. This book has originated from an effort to bring together the research communities of software architectures, dependability and security. This state-of-the-art survey contains expanded and peer-reviewed papers based on the carefully selected contributions to two workshops: the Workshop on Architecting Dependable Systems (WADS 2008), organized at the 2008 International Conference on Dependable Systems and Networks (DSN 2008), held in Anchorage, Alaska, USA, in