In this chapter, the development and evolution of Web Applications is viewed from an engineering perspective that relies on and accommodates the knowledge inherent in patterns. It proposes an approach in the direction of building a foundation for pattern-oriented Web Engineering. For that, a methodology for pattern-oriented Web Engineering, namely POWEM, is described. The steps of POWEM include selection of a suitable development process model, construction of a semiotic quality model, namely PoQ, and selection and mapping of suitable patterns to quality attributes in PoQ. To support decision making and to place POWEM in context, the feasibility issues involved in each step are discussed. For the sake of is illustration, the use of patterns during the design phase of a Web Application are highlighted. Finally, some directions for future research, including those for Web Engineering education and Social Web Applications, are given.