This book presents 14 recent papers that provide an overview of the latest software reliability models, testing techniques, and applications. The book is targeted toward design engineers, software engineers, researchers, computer scientists, technical managers, and students wishing to conduct research or update their knowledge in the field of software reliability and testing. The papers on software reliability describe applications of software reliability growth modeling to software systems, investigate the relationship between program complexity measures and program errors, and explore the difficulty in accurately modeling software reliability. The remaining papers present new models that are useful in estimating the reliability of software systems and deal with the cost-reliability-optimal software release policies in software systems. The papers on software testing investigate the relationship between reliability and testing, discuss safety arguments and the role of software and system reliability and describe the use of an operational profile in testing a large-scale industrial software system for estimating software. The remaining papers present new models useful in testing software systems.