Ah, this reminds me of the days I spent writing RPL programs for solving electric circuits on my trusty old HP48 calculator. (It is said but nowhere officially

Ah, this reminds me of the days I spent writing RPL programs for solving electric circuits on my trusty old HP48 calculator. (It is said but nowhere officially confirmed that RPL stands for "reverse-polish lisp".) It was quite enjoyable _then_ and for _that_ purpose (programs designed to run in a specific UI environment) but today I wouldn't even consider starting a "serious" project in a postfix language. EDIT: https://factorcode.org/ https://factorcode.org/ is a modern postfix language. Using weird languages DOES have one merit though: it opens your horizons. It teaches you to see a "conventional" programming language as a collection of mechanisms at your disposal instead of something "intended to be used to do X". More to the point, I think that there are two types of languages: 1) those that encourage top-down design (that's how I learned programming with Pascal) and 2) those that encourage bottom-up design (such as RPL, these have often an interactive REPL.) So actively using something like RPL or ML or Scheme (yeah, I've read ca 2/3 rds of SICP) allows you to turn C# "inside out", to apply bottom-up programming techniques. You don't create a class because "some OO principles tell you to do so" or because it came as godsend from some "architect", but because you understand workings of classes and a class is the right tool for the task at hand. Also, there's no programming in the large without some mechanisms to control accessibility.