Dias, José Miguel SallesBastos, RafaelSantos, PedroMonteiro, LuísCanhoto, JoaquimCarriço, Luís and Correia, Nuno and Antunes, Pedro and Jorge, Joaquim2021-11-022021-11-022021978-3-03868-166-3https://doi.org/10.2312/pt.20041502https://diglib.eg.org:443/handle/10.2312/pt20041502ln this paper we introduce the Arena, an indoor space for mobile mixed reality interaction. The Arena, includes a new user tracking system appropriate for ARJMR applications anda new Too/kit oriented to the augmented and mixed reality applications developer, the MX Too/kit. This too/kit is defined at a somewhat higher abstraction levei, by hiding from the programmer low levei implementation details and facilitating ARJMR objectoriented programming. The system handles in a uniform way, video input, video output (for head-sefs and monitors), sound aurelisation and Multimodal Human-Computer Interaction in ARJMR, including, tangible interfaces, speech recognition and gesture recognition.Augmented Reality (AR)Mixed Reality (MR)Tangible InterfacesAR Too/kitUser TrackingUltra Sound TrackingWearable10.2312/pt.20041502109-119