This volume investigates the historical development and technical philosophy behind the Smalltalk-80 programming environment. The author, Glenn Krasner, compiles insights from the original Xerox PARC research team to document the evolution of object-oriented programming. The text serves as a retrospective on the design decisions that shaped one of the most influential graphical user interface systems in computing history.

Computer science historians and software engineers frequently cite this text as a primary source for understanding the origins of modern object-oriented programming. Experts highlight the book for its unique combination of technical documentation and firsthand institutional history.