Future database systems must feature extensible data models and data languages in order to accommodate the novel data types and special-purpose operations that are required by nontraditional database applications. In this paper, we outline a functional data model and data language that are targeted for the semantic interface of GENESIS, an extensible DBMS. The model and language are generalizations of FQL [11] and DAPLEX [40], and have an implementation that fits ideally with the modularity required by extensible database technologies. We explore different implementations of functional operators and present experimental evidence that they have efficient implementations. We also explain the advantages of a functional front-end to ¬1NF databases, and show how our language and implementation are being used to process queries on both 1NF and ¬1NF relations.