SpeedCrunch
Open Source
SpeedCrunch is a high-precision scientific calculator featuring a fast, keyboard-driven user interface.
Calcbot
Freemium
Calcbot is a intelligent calculator and unit converter.
Mathematica
Commercial
Wolfram Mathematica (usually termed Mathematica, Mathematica software suite) is a mathematical symbolic computation program.
Compare Soulver with alternatives
Compare SpeedCrunch and Soulver and decide which is most suitable for you.
Compare Mathematica and Soulver and decide which is most suitable for you.