Open distributed systems we are going to conceive in the future will present challenging design and operating requirements demands. Integrating dynamically autonomous distributed modules, allowing module reuse, coping with specific user requirements, such as QoS, are going to be common tasks a designer will have to face. In this context, it is convenient to make available suitable models to design such systems and provide flexibility to handle dynamic requirements.

This paper presents and evaluates two paradigms that have been proposed as solutions to provide mechanisms for modular and flexible distributed system programming: configuration and computational reflection. The concepts are discussed, and the situations were the use of each of them is best suitable are pointed out. Both paradigms, lead to mechanisms that intend to facilitate the accomplishment of functional and non-functional application requirements. The fitness of these paradigms for the construction of large systems, with focus on multimedia distributed applications, is discussed. Based on this study, some comparisons between the configuration and reflection techniques is performed. The main conclusion is that these techniques can be used in a complementary way and be applied at different granularity levels.