A stack-oriented programming language is one that relies on a stack machine

Stack machine

A stack machine may be* A real or emulated computer that evaluates each sub-expression of a program statement via a pushdown data stack and uses a reverse Polish notation instruction set....

 model for passing parameters. Several programming languages fit this description, notably Forth, RPL, PostScript

PostScript

PostScript is a dynamically typed concatenative programming language created by John Warnock and Charles Geschke in 1982. It is best known for its use as a page description language in the electronic and desktop publishing areas. Adobe PostScript 3 is also the worldwide printing and imaging...

, and also many Assembly language

Assembly language

An assembly language is a low-level programming language for computers, microprocessors, microcontrollers, and other programmable devices. It implements a symbolic representation of the machine codes and other constants needed to program a given CPU architecture...

s (but on a much lower level).

Stack-oriented programming languages operate upon one or more stack

Stack (data structure)

In computer science, a stack is a last in, first out abstract data type and linear data structure. A stack can have any abstract data type as an element, but is characterized by only three fundamental operations: push, pop and stack top. The push operation adds a new item to the top of the stack,...

s, each of which may serve different purposes. Because of this, programming constructs in other programming languages may need to be modified for use in a stack-oriented programming language.