The Tangible Tracking Table (TTT) is an interactive tabletop display that allows both fingertip and tangible object tracking. Multiple users can simultaneously control a variety of tagged objects that can perform different tasks. At the same time, users can employ their fingertips for more subtle manipulations. TTT can support a range of digital media applications in collaborative settings, such as meeting rooms, classrooms and living rooms. Applications under development include games and storytelling engines, as well as a stage manager for machinima creation. The TTT project includes the construction of the table and adapted software APIs based on the ReacTIVision toolkit for user-end application development. The TTT intends to be:</p>- Collaborative: several users can interact with the table at once, for example towards a shared set of goals,<br />- Suitable for novice users: moving everyday physical objects is more intuitive than operating traditional interfaces such as keyboards and mice, and<br />- Educational: the APIs for multiple programming environments allow students to create applications using their preferred high-level development tools<br /><p>To explore more functional possibilities, the first prototype (TTT I) adopted two popular technologies that are used in many multitouch displays today, the "Frustrated Total Internal Reflection" (FTIR) and the "Diffused Illumination" (DI) approaches. The second table (TTT II) uses DI and installs two mirrors to increase the display and interaction surface to 55 inches.