Object-oriented database systems provide an approach to representing and manipulating complex objects that has received wide attention for scientific and engineering applications. The view-object model is an alternative approach that builds on the relational data model to define complex entities. In this paper, we present an implementation of the model in the PENGUIN system that defines an object-oriented layer on top of a relational database. This domain-independent architecture permits object-oriented access to information stored in relational format-information that can be shared among applications. The capabilities of PENGUIN are demonstrated and the potential benefits of this methodology for developing enhanced information systems are discussed. © 1990.