The prevailing architecture for web-based applications relies on HTML, HTTP and loosely integrated functional elements, propagating a strong distinction between client and server. The proposed approach for active hypertext documents however realizes applications through hypertext documents with embedded application logic. Furthermore, the need for separating the approach into a model, a development method and supporting tools is identified. The core model is based on open standards such as XML and CSS. It is extended by idioms which describe important concepts and reusable constructs. Examples for the application of the model are given.