The Polymorphic Programming Language (PPL) was developed in 1969 at

Harvard University Harvard University is a Private university, private Ivy League research university in Cambridge, Massachusetts, United States. Founded in 1636 and named for its first benefactor, the History of the Puritans in North America, Puritan clergyma ...

by Thomas A. Standish. It is an

interactive Across the many fields concerned with interactivity, including information science, computer science, human-computer interaction, communication, and industrial design, there is little agreement over the meaning of the term "interactivity", but mo ...

extensible Extensibility is a software engineering and systems design principle that provides for future growth. Extensibility is a measure of the ability to extend a system and the level of effort required to implement the extension. Extensions can be th ...

language with a

base language In the tree model of historical linguistics, a proto-language is a postulated ancestral language from which a number of attested languages are believed to have descended by evolution, forming a language family. Proto-languages are usually unattest ...

similar to the language APL. The assignment operator <- (or ←) has influenced the language S.

References

Procedural programming languages Harvard University Programming languages created in 1969 {{compu-lang-stub