"RPL/2 or Reverse Polish Lisp/2 is a particular language, in the etymological sense of the term, which could be the result of the forbidden loves between Lisp a

"RPL/2 or Reverse Polish Lisp/2 is a particular language, in the etymological sense of the term, which could be the result of the forbidden loves between Lisp and Forth. It takes in Forth its reversed polish notation and its stack addressing, but keeps only one standardized stack, and in Lisp, the power of its control structures." Heh, forbidden love. Very cute, but the project seems to be inactive, and while the interpreter is free, the compiler is closed source and expensive. I think this is of not much interest unless you want to make an HP calculator clone or something. Otherwise the GNU Emacs calculator (calc.el) is afaict a lot more powerful than the old HP's were, and after that there are programs like Sage. Also, there are other RPL implementations out there. I don't think I've used a calculator (including calculator apps) for anything more than simple purposes in years. Otherwise I end up using Python or whatever.