Smalltalk is a purely object oriented programming language (OOP), created in the 1970s for educational use, specifically for constructionist learning, at Xerox PARC by Learning Research Group (LRG) scientists, including Alan Kay, Dan Ingalls, Adele Goldberg, Ted Kaehler, Diana Merry, and Scott Wallace.
In Smalltalk, executing programs are built of opaque, atomic, so-called objects, which are instances of template code stored in classes. These objects intercommunicate by passing of messages, via an intermediary virtual machine environment (VM). A relatively small number of objects, called primitives, are not amenable to live redefinition, sometimes being defined independently of the Smalltalk programming environment.
Having undergone significant industry development toward other uses, including business and database functions, Smalltalk is still in use today. When first publicly released, Smalltalk-80 presented innovative and foundational ideas for the nascent field of object-oriented programming (OOP).