Banerjee, SumanAgarwal, SulabhKamel, KevinKochut, AndrzejKommareddy, ChristopherNadeem, TamerThakkar, PankajTrinh, BaoYoussef, AdelYoussef, MoustafaLarsen, RonShankar, A. UdayaAgrawala, AshokLocation-aware computing involves the automatic tailoring of information and services based on the current location of the user. We have designed and implemented Rover, a system that enables location-based services, as well as the traditional time-aware, user-aware and device-aware services. To achieve system scalability to very large client sets, Rover servers are implemented in an "action-based" concurrent software architecture that enables fine-grained application-specific scheduling of tasks. We have demonstrated feasability through implementations for both outdoor and indoor environments on multiple platforms. (Also UMIACS-TR 2001-89)en-USTechnical Report