I'm guessing from the names I see here that this is an RPN calculator application; as such, its best namespace would be App::, and I'd recommend App::Calculator::RPN or maybe App::RPNCalc. (I'd also change the calc.pl to rpncalc or calc_rpn, as those are less likely to collide with someone else's name.)

I'd put a vote in for Dist::Zilla as a possible tool for you as well. There's an intro to it here. (I haven't switched to it yet but I'm strongly considering it.)

One of the nice things about using one of the standard build tools is that they all have a make dist or equivalent command that builds your tar.gz file for you. They also have a make test, which is also a good habit to get into using.