I am seeking any open source libraries that exist to do the floating point calculations precisely the way that HP calculators do in the hope of re-creating the Voyager Series calculators on the iPhone (as an app in the App Store). The form factor of the iPhone is so similar to the Voyager series, it begs for an authentic HP emulator that retains the accuracy and functionality of the HP-10/11/12/15/16 series.
There are a handful of RPN calculators on the App Store but none look like the HP Voyagers. A full emulator will reproduce the buttons and faceplate precisely -- getting the numbers to match is a crucial bonus.