A scalable middleware solution for QoS-aware multimedia service delivery in the ubiquitous computing environment remains a challenging problem. Its heterogeneous and dynamic nature demands a more flexible and intelligent framework. We present SMART, a self-reconfigurable component-based middleware solution to address this issue. The system responds to the reconfiguration requests from applications and users to offer extensibility and efficiency. Furthermore, we present an active controlling mechanism, in which the middleware is able to adapt to the environment variation in a timely fashion. In addition, we describe user management in our framework, which preserves our user-centric philosophy. Finally, we discuss MobiMan, an integrated multimedia service platform as the proof-of-concept application of SMART.