Hoc, the High Order Calculator, is an interpreted language for
floating-point calculations. Its most basic use is as a powerful and
convenient calculator, interactively evaluating expressions such as
1+2*sin(0.7). But hoc is no ordinary calculator: It also lets you
assign values to variables, define your own functions, and use loops,
conditionals, and everything else you'd expect in a programming
language.

Hoc was developed by Brian Kernighan and Rob Pike, and introduced in
their 1984 book The Unix Programming Environment. This version has been
extended and improved by Nadav Y. Har'El.

WWW: http://nadav.harel.org.il/homepage/hoc/