This book constitutes the refereed proceedings of the 12th International Conference on Reliable Software Technologies, Ada-Europe 2007, held in Geneva, Switzerland, in June 2007.

The 18 revised full papers presented were carefully reviewed and selected from numerous submissions. The papers address all aspects of reliable software technologies, such as methods and techniques for software development and maintenance, software architectures, enabling technology, software quality, critical systems, distributed systems, as well as Ada language and technology.