This paper presents an architectural framework for customizing Object Request Broker (ORB) implementations to application-specific preferences for various non-functional requirements. ORB implementations are built by reusing a domain-specific component-based architecture that offers support for one or more non-functional requirements. The domain-specific architecture provides the mechanism that allows the ORB to reconfigure its own implementation at run-time on the basis of application-specific preferences. This mechanism is based on a run-time selection between alternative component implementations that guarantee different service-levels for non-functional requirements. Application-specific preferences are defined in policies and service-level guarantees are defined in component descriptors. Policies and component descriptors are expressed using descriptive languages. This gives application programmers an easy and powerful tool for customizing an ORB implementation. To validate the feasibility of our architectural framework we have applied it in the domain of robotic control applications.