Haskell.

This obscure language represents a peculiar corner of the programming language world called functional languages. One of the peculiar things about such languages is that they don’t have variables. Although Haskell isn’t widely known among programmers, those who know of functional languages suspect that they, too, are rather slow

>>42
I'm not >>39, but in lambda calculus, arguments are called ``bound variables´´, extern bindings (from the outer scope) are called ``free variables´´.
In mathematics, a variable is indeed ``constant'', you don't setf them in the middle of an expression, but they can be any value, depending on what the function is called with.

Now, we all know that Haskell is for pure functional mathematical faggots, therefore it has variables, in the mathematical sense.

The bound variables/free variables thing applies also to Lisp, due to its resemblance with lambda calculus.