In this paper we present a web-based framework for spatiotemporal screen real estate management of interactive public displays. The framework facilitates dynamic partitioning of the screen real estate into virtual screens assigned for multiple concurrent web applications. The framework is utilized in the implementation of so-called UBI-hotspot, which provides various information services via different interaction modalities including mobile. The framework facilitates seamless integration of third party web applications residing anywhere in the public Internet into the UBI-hotspot, thus catering for a scalable and open architecture. We report the deployment of a network of indoor and outdoor UBI-hotspots at downtown Oulu, Finland. The quantitative data on the usage of the UBI-hotspots implicitly speaks in favor of the practical applicability of the framework.