xRPN is a free and easy to use, heavy duty RPN calculator. xRPN has the ability to calculate factorials of upwards of 100,000,000,000,000 (that`s 100 trillion, but it takes a LONG time to calculate).
xRPN has most of the basic functions of any calculator (most of the goodies like lcm will be back in the next release). Most of the operations and interactions with the stack mimic that of an HP-49G.
Some more information on how to use xRPN is available in the Readme file contained in the archive.
