I think RPN was initially adopted for electronic calculators because it is easy to implement. As numbers are entered, they are pushed onto the stack, and then the operations pop operands off of the stack and push results back on the stack. Similarly, code in an RPN language like Forth can be executed left-to-right by pushing the operands onto the stack, and then the operation manipulates the contents of the stack.
I am not sure it does, but:
(7 + 2) * (2 + 5) in normal, infix notation
* + 7 2 + 2 5 in polish notation, http://en.wikipedia.org/wiki/Polish_notation
vs reverse polish which is:
7 2 + 2 5 + * (or 7 2 25 + + * ) which is easy to evaluate, but not necessarily to read)
Sorry, I should have added some context:
>Notice that RPN requires no parenthesis, unlike the polish notation of Lisps where the operator comes first, and RPN requires no precedence rules, unlike the infix notation used in most programming languages and in everyday arithmetic.
This seems wrong to me. It's the lack of variadic functions that is the relevant difference to lisp in terms of doing away with parens, not PN vs RPN.
Love the article, though
Unless your operators don't have a fixed arity, anyhow (Lisp's don't). But even then I don't see how RPN is in a better position...