Smalltalk

Smalltalk is a pure object-oriented language, simple and uniform. Smalltalk influenced most of the modern object-oriented languages, although most of the time they missed Smalltalk's elegance and simplicity.

The syntax of Smalltalk fits into one postcard and the object model is simple:

• Everything is an object.
• Objects communicate via message passing.
• Classes describe in terms of state (instance variables) and behavior (methods) the objects they generate.
• When an object receives a message, the corresponding method is looked up in the class (and superclass) of the receiver.
• Methods are public.
• Instance variables are private.
• Classes inherit via single inheritance.

Here is an example of Smalltalk (using Squeak's Morphic GUI classes) that creates an ellipse, changes its color to blue and shows it on the screen:

You can find more information on Smalltalk at Documentation

Other Smalltalk Implementations

Smalltalk Implementations listed on smalltalk.org

Smalltalk Implementations listed in Wikipedia

Smalltalk Implementations listed in Google's Directory