This book investigates the design principles and practical implementation of the Smalltalk-80 system as a fully integrated interactive programming environment. Adele Goldberg, a key researcher at Xerox PARC, provides a comprehensive technical breakdown of the language's architecture, the virtual machine, and the user interface paradigms that defined the system. The text serves as the definitive reference for understanding how object-oriented programming concepts were operationalized within the Smalltalk-80 framework.

Experts recognize this work as a foundational text in the history of object-oriented programming and graphical user interfaces. Readers frequently note the high technical density of the prose, which is intended for software engineers and computer science researchers.