In this paper we describe TANGerINE, a tangible tabletop environment in which users can interact with digital contents manipulating tangible smart objects. Such objects provide continuous data about their status through the embedded wireless sensors, while an overhead computer vision module tracks their position and orientation. Merging sensing data, the system is able to detect a richer language of gestures and manipulations both on the tabletop and in its surroundings, enabling for a more expressive interaction language across different contexts.

We present an interactive workspace that integrates wiki collaboration in knowledge-building activities with face-to-face scenarios like brainstorming or problem solving sessions. A wiki serves as the repository for knowledge elements, which are presented to co-located users in form of a concept map projected on a table. A computer vision module tracks multiple hands and fingers on the table surface and map elements can be manipulated using a simple gesture language. Also smart devices, like PDAs or tablets, can be connected to the system and participate in the interaction with their local input. The concept map and the wiki are synchronized in real-time, providing notifications to both co-located and distributed users and allowing a community shared awareness that enhances and enriches the knowledge building experience