In this paper, we present IrisTK - a toolkit for rapid development of real-time systems for multi-party face-to-face interaction. The toolkit consists of a message passing system, a set of modules for multi-modal input and output, and a dialog authoring language based on the notion of statecharts. The toolkit has been applied to a large scale study in a public museum setting, where the backprojected robot head Furhat interacted with the visitors in multiparty dialog.