Smalltalk is a pioneering object-oriented programming language developed at Xerox PARC in the 1970s. Created by Alan Kay and his team, it introduced many concepts that define modern programming and graphical user interfaces.
Origins at Xerox PARC
Alan Kay conceived Smalltalk as a programming language that could be used by children. Influenced by Lisp’s flexibility and Simula’s object concepts, Kay and his team—including Dan Ingalls and Adele Goldberg—created a language where “everything is an object.”
Key Innovations
Smalltalk pioneered fundamental programming concepts:
- Pure Object-Orientation: Everything, including numbers and classes, is an object
- Message Passing: Objects communicate by sending messages
- Integrated Development Environment: First true IDE with debugger and browser
- Model-View-Controller (MVC): The architectural pattern for user interfaces
- Live Programming: Modify running programs without restarting
Graphical User Interface
Smalltalk was inseparable from its graphical environment. The Smalltalk system featured overlapping windows, pop-up menus, and graphical editing—innovations that Steve Jobs famously saw during his visit to Xerox PARC and later incorporated into the Macintosh.
Impact
Though Smalltalk itself never achieved mainstream adoption, its ideas pervade modern software: Java, Ruby, Python, and Objective-C all draw from Smalltalk’s design. The IDE concept, unit testing, and agile development practices all trace back to the Smalltalk community.