OpalCalc is a free, user-friendly and intuitive calculator that is designed to make everyday calculations easy and efficient. It is an advanced yet simple-to-use calculator that can be used for a variety of calculations such as basic arithmetic, scientific calculations, currency conversions, and more. It also provides a range of useful functions, including graphing, algebraic equations, and statistical analysis. OpalCalc is available as a stand-alone application for Windows and Mac, and can also be used as a web application. It is designed to be an intuitive and powerful tool for anyone who needs to make calculations quickly and accurately.
Very, very similar to opal. For less vigorous calculations the speed is better. For more complex calculations, opal, the full version is better with a slightly higher learning curve.