Object-oriented programming techniques are known to improve the flexibility and reusabillty of certain kinds of software. Libraries of object classes, however, continue to be difficult both to develop and to reuse. We present an approach to object-oriented application development in which applications are constructed by interactively ''scripting" cooperating, reusable software objects. A visual scripting tool is being developed within ITHACA, an Esprit II project which seeks to produce an integrated environment for the rapid and flexible development of object-oriented applications for selected application domains.