Modern scientific experiments can generate large amounts of data, which may be replicated and distributed across multiple resources to improve application performance and fault tolerance. Whilst a number of different replica management systems exist, particular communities usually adopt a single system. This creates problems when an application program spans more than one community, because it may need to target more than one middleware layer. One solution to this problem is to build a more flexible data access layer above the specific replica middleware. In this paper, we discuss such an architecture, the Grid Replication Framework, which provides applications with an abstract interface to existing replica systems. Further, the framework?s flexible plug-in architecture makes it easy to support new middleware as it becomes available.