Since 1990 the Web has changed from a distributed hypertext system to an efficient environment for application delivery. Due to the legacy of the Web implementation model the development, management, and evolution of complex Web applications suffer from the coarse-grained model-entities. The demands can not be achieved without the application of programming technology and software engineering practice to applications in the Web, which is also referred to as Web Engineering. It has been recognized that the gap between design models and the implementation model of the Web leads to a development process that is hard to maintain, because fine-grained design entities get lost in the coarse-grained implementation model. Therefore, the coarse-grained implementation model hinders the maintenance and reuse of parts of an application. In this paper, the impacts on Web Engineering due to the coarse-grained Web implementation model are discussed and typical solutions that are related to the above problems are introduced. Then, the object-oriented WebComposition Markup Language will be presented as basis for a generic approach to component-based Web-application development.