The success of many innovative Web applications is not based on the content they produce ? but on how they combine and link existing content. Older Web Engineering methods lack flexibility in a sense that they rely strongly on a-priori knowledge of existing content structures and do not take into account initially unknown content sources. We propose the adoption of principles that are also found in Component-based Software Engineering, to assemble highly extensible solutions from reusable artifacts. The main contribution of our work is a support system, consisting of a central service that manages n:m relationships between arbitrary Web resources, and of Web application components that realize navigation, presentation, and interaction for the linked content. Categories and Subject Descriptors D.2.13 [Software Engineering]: Reusable Software ? reusable libraries. H.5.4 [Information Interfaces and Presentation]: Hypertext / Hypermedia ? Architectures General Terms Management, Design Key...