J
APL successor from Kenneth Iverson using ASCII symbols — array-oriented and extraordinarily expressive for mathematical computing.
dynamic
interpreted
since 1990
arrayfunctionaltacit
J is Kenneth Iverson’s redesign of APL using ASCII characters instead of special symbols. Like APL, it operates natively on arrays — a single expression can process an entire dataset. Tacit (point-free) programming style allows composing verbs without naming arguments. J is used in quantitative finance and mathematical research where dense, exact notation matters.