Once a radical notion, object-oriented programming is one of today's most active research areas. It is especially well suited to the design of very large software projects involving many programmers all working on the same project. The original contributions in this book will provide researchers and students in programming languages, databases, and programming semantics with the most complete survey of the field available. Broad in scope and deep in its examination of substantive issues, the book focuses on the major topics of object-oriented languages, models of computation, mathematical models, object-oriented databases, and object-oriented environments. The object-oriented languages include Beta, the Scandinavian successor to Simula (a chapter by Bent Kristensen, whose group has had the longest experience with object-oriented programming, reveals how that experience has shaped the group's vision today); CommonObjects, a Lisp-based language with abstraction; Actors, a low-level language for concurrent modularity; and Vulcan, a Prolog-based concurrent object-oriented language. New computational models of inheritance, composite objects, block-structure layered systems, and classification are covered, and theoretical papers on functional object-oriented languages and object-oriented specification are included in the section on mathematical models. The three chapters on object-oriented databases (including David Maier's "Development and Implementation of an Object-Oriented Database Management System," which spans the programming and database worlds by integrating procedural and representational capability and the requirements of multi-user persistent storage) and the two chapters on object-oriented environments provide a representative sample of good research in these two important areas. Bruce Shriver is a researcher at IBM's Thomas J. Watson Research Center. Peter Wegner is a professor in the Department of Computer Science at Brown University. Research Directions in Object-Oriented Programmingis included in the Computer Systems series, edited by Herb Schwetman.