Authoring dynamic web pages is an inherently difficult task. We present DESK, an interactive authoring tool that allows the customization of dynamic page generation procedures with no apriori tool-specific skill requirements from authors. Our approach consists of combining Programming By Example (PBE) techniques with an ontology-based representation of knowledge displayed in web pages. DESK acts as a client-side complement of a dynamic web page generation system, PEGASUS, which generates HTML pages from a formally structured domain model bstract presentation model. Authorized users can modify the internal presentation model by editing the generated HTML pages with DESK in a WYSIWYG environment. DESK keeps track of all user’s actions and exploits the explicitly represented domain semantics to enhance the power of PBE techniques. Categories and Subject Descriptors H.5.2 [Information Interfaces And Presentation]: User Interfaces – Graphical user interfaces (GUI), Screen Design, Inter...