Smalltalk

From GTALUG

Smalltalk

Wikipedia:Smalltalk is one of the "classic" object oriented languages. It was created at Xerox PARC by Alan Kay, in a project that started in 1969; it was first released as Smalltalk-80, in around 1980. It was initially created in a few mornings on a bet that a programming language based on the idea of message passing inspired by Simula could be implemented in "a page of code."

The syntax of Smalltalk is exceedingly minimalist, based on only a few declarations and reserved words. The only built-in language constructs are message sends, assignment, method return and literal syntax for certain sorts of objects. The remainder of the language, including control structures like loops and conditionals, are implemented on top of the base objects. Unlike languages with more "mixed" models, like C++, Smalltalk really is "objects all the way down."

Smalltalk environments tend to start with a virtual machine that implements the built-in constructs, combined with a memory image that implements a class structure on top of that, which typically includes an entire self-contained programming environment capable of modifying itself.