In this article, we present our efforts1 on realizing transformation independence in open, extensible, and highly distributed multimedia information The main focus is on the abstract data and processing model called VirtualMedia which provides to application developers a kind of ’metaprogramming’interface for multimedia processing. In particular, we describe how transformation requests are represented and processed, exploiting semantic equivalence relations on filter graphs and redundant materialization, finally yielding instantiatable plans for materializing the requested media object(s) at the client. The article concludes with a brief outlook on future research objectives.