MPCalc Plugin allows a Xojo developer to design a multi-precision RPN calculator. It could handle numbers with up to 30,000 decimal digits. It could also handle numbers whose absolute values lie between 1e-65000000 and 1e+65000000. It is a 32- and 64-bit plugin for OS X. Over forty scientific functions are now available.
Note: Now requires OS X 10.7.5 or later.