The tool GENVIS supports the integration of an XML data repository with different GUI frameworks. It maps a model of an XML data repository to an abstract grid-based layout model. This mapping on model level combined with a flexible template mechanism allows generating source code for data visualizers, which construct well-formatted views on XML documents. GENVIS generates data visualizers for different GUI frameworks. The tool is productively used to construct report visualizers for a credit risk report management system of a leading Swiss Bank. GENVIS was developed with the prototyping environment APICES. Since large parts of the tool were generated from meta-models of the repository and the layout, we were able to construct it at reasonable costs and effort in a very short time.