(APL) A programming language designed originally by Ken Iverson at Harvard University in 1957-1960 as a notation for the concise expression of mathematical algorithms. It went unnamed (or just called Iverson's Language) and unimplemented for many years. Finally a subset, APL360, was implemented in 1964. APL is an interactive array-oriented language and programming environment with many innovative features. It was originally written using a non-standard character set. It is dynamically typed with dynamic scope. APL introduced several functional forms but is not purely functional. Dyalog APL/W and Visual APL are recognized .NET languages. Dyalog APL/W, APLX and APL2000 all offer object-oriented extensions to the language. ISO 8485 is the 1989 standard defining the language.