NORMA is a handy tool for interactive network annotation, visualization and topological analysis, able to handle multiple networks and annotations simultaneously. Annotations and/or node groups can be precomputed or automatically calculated and users can combine several networks and groupings they are interested in. Annotated networks can be visualized using both pie-chart nodes and shaded convex hulls and can be shown using several layouts while users can isolate the groups of interest interactively. In addition, NORMA is suitable for direct comparison of topological features between one or more networks.