RPN Calculator 3.01 source code (C++) is available for non-commercial use at no charge. Please email for more information. To compile all versions, you will need Visual Studio 2005 plus several SDKs.

** [Feb 2, 2007] by T1 using Audiovox 6700
Too hard to use. I would rather see a simulation of HP14C RPN or the like. I was intrigued because it supports binary/hex as well as scientific but I couldn't get past the initial learning curve. I couldn't figure out how to add 1+1. Sorry but true.