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, and 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). Since inception, the language provided interactive programming via an integrated development environment. This requires reflection and late binding in the language execution of code. Later development has led to at least one instance of Smalltalk execution environment which lacks such an integrated graphical user interface or front-end. Smalltalk-like languages are in active development and have gathered loyal communities of users around them. ANSI Smalltalk was ratified in 1998 and represents the standard version of Smalltalk. Smalltalk took second place for "most loved programming language" in the Stack Overflow Developer Survey in 2017, but it was not among the 26 most loved programming languages of the 2018 survey. History There are a large number of Smalltalk variants. The unqualified word Smalltalk is often used to indicate the Smalltalk-80 language and compatible VM, the first version to be made publicly available and created in 1980. The first hardware-environments which ran the Smalltalk VMs were Xerox Alto computers. Smalltalk was the product of research led by Alan Kay at Xerox Palo Alto Research Center (PARC); Alan Kay designed most of the early Smalltalk versions, Adele Goldberg wrote most of the documentation, and Dan Ingalls implemented most of the early versions. The first version, termed Smalltalk-71, was created by Kay 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". A later variant used for research work is now termed Smalltalk-72 and influenced the development of the Actor model. Its syntax and execution model were very different from