16 Alternatives To OpalCalc
SpeedCrunch. SpeedCrunch is a high-precision scientific calculator featuring a fast, keyboard-driven user interface. It is free and open-source software, licensed under the GPL. Download Documentation Donate .
fxSolver is an free online math solver, equation library, graphing calculator and science/engineering problem helper. To get started, add some formulas, fill in any input variables and press “Solve.”