1. 8

  2. 7

    This is my favourite PLT paper.

    Although the term “functional programming” was already in use (to describe Lisp), this paper is actually the original functional programming manifesto that led to modern functional programming languages like SML, OCaml, F#, Haskell and Idris. The language it describes (ISWIM) is the ancestor of all the languages I listed, via ML. Note that Landin had previously invented lexically scoped closures (in 1964), a key functional programming feature that Lisp didn’t adopt until much later (some time in the 1970s).