The integration of multimedia into heterogeneous computer applications exposes the need for context-sensitive multimedia objects which can adapt to the fluctuating resources and needs of the application. The typical model of a multimedia application is to give the application access to a library of static multimedia objects. System management of the presentation is limited to synchronization. We contend that multimedia objects should be dynamic and adaptable to their application environments. At the very least, multimedia objects should be scalable in terms of resource usage, e.g., the use of screen space, network bandwidth, and computational resources. Multimedia objects should also be able to alter their modes of representation in response to the changing needs of the user. Finally, multimedia objects should be capable of altering their content to fit the preferences of the user and the context of the presentation. We present a multimedia distribution system called O, which enables the creation of dynamic multimedia objects for distribution over a network. These objects are `self-aware,' in that they can be programmed with the behaviors necessary to respond to a changing presentation environment. O is featured as the multimedia distribution tool in both a personalized information retrieval application and a mapping application.