Existing distributed middleware technologies and Enterprise Application frameworks lack in support to service flexibility from both the developer’s and user’s point of view. In this paper we propose a JINI-based framework, namely PRINCEPS (Pluggable Reliable Infrastructure for Network Computing and Enhanced Properties of Service), which provides a distributed and dynamic environment for flexible service provision. We claim that the adoption of JINI makes it possible to dramatically improve service flexibility by federating services in a dynamic and self-healing networked community. The framework provides the clients with a (web-based) mechanism for selecting services according to functional requirements (i.e., the service interface)and non-functional requirements (the quality of service, i.e., reliability, performance). More implementations of the same service can coexist in the framework, each of one satisfying different non-functional requirements. PRINCEPS provides service s...