||Web applications have developed into an essential communication platform for many companies. Web applications are crucial for commerce, information exchange, and a host of social activities. For this reason Web applications have to offer high-performance, reliable, and easy-to-use services round the clock. Offering excellent Web applications for existing and future users represents a major challenge for quality assurance. Testing is one of the most important quality assurance measures. Traditional test methods and techniques concentrate largely on testing functional requirements. Unfortunately, they do not focus enough on the broad range of quality requirements, which are important for Web application users, such as performance, usability, reliability, and security. Furthermore, a major challenge of testing Web applications is the dominance of change. User requirements and expectations, platforms and configurations, business models, development and testing budgets are subject to frequent changes throughout the lifecycle of Web applications. It is, therefore, necessary to develop an effective scheme for testing that covers the broad range of quality characteristics ofWeb applications and handles the dominance of change, helping to implement and better understand a systematic, complete, and risk-aware testing approach. Such a test scheme forms the basis for building an exemplary method and tool box. Practical experience has shown that methodical and systematic testing founded on such a scheme is feasible and useful during the development and evolution of Web applications.