Preferred calculator program language

[Claudio L.]

I like RPL for quick prototyping, and because it integrates really well with the way the stack works (which in turn integrates really well with my brain's workflow). However, RPL gets complicated for larger projects, especially when "stackrobatics" are used. In my case I decided to improve RPL rather than switching to another language. I think it got a lot better (talking about newRPL of course) with easy to create and use local variables, combined with persistent comments, but I still need to convince the larger audience to use it like that instead of trying the same old stackrobatics (which I admit, I fall for all the time). RPL code looks very different when written that way.

As far as other (calculator?) languages, the one I like most is Lua for it's extreme simplicity (much like BASIC) while still being very clean and readable.
Even though I don't use it much, I like the way it's designed: simple flow structures (like BASIC), no complicated types, no complicated syntax, no annoying forced indentation (looking at you, Python), no null pointers (now aiming my cannons at C).
Unfortunately it's falling out of favor vs. python, which is quickly becoming the standard for interpreted languages.