While things like object oriented computing and model-view-controller are old hat these days, when Smalltalk burst on the scene, many people had never heard of these new ideas. While the little language with roots at Xerox and based on Simula never caught fire, it was very influential in a number of ways. Now Smalltalk luminary [Dan Ingalls] has the Smalltalk Zoo, a collection of Smalltalk-related items including several historical simulations you can run in your browser.
In Smalltalk everything is an object. With things like the turtle graphics object (@) and you can say things like:
@ go 50 turn 90 go 50 turn 90 go 50 turn 90 go 50\
It is less amusing when someone tells you they sent the + message to the 3 object in order to add something to 3, but that’s object-orientation for you. If you don’t know Smalltalk, try the snippets you can find on the right side of the emulator.