Wolfram Alpha
Freemium
Wolfram Alpha is a computational knowledge engine or answer engine developed by Wolfram Research.
Sage
Open Source
Sage offers business management, bookkeeping & accounting software to meet any business need, from small to midsized businesses.
Swift Calcs
Free
Swift Calcs enables users to effortlessly create and collaborate on interactive computational documents, from any device.
Mathematica
Commercial
Wolfram Mathematica (usually termed Mathematica, Mathematica software suite) is a mathematical symbolic computation program.
fxSolver
Free
fxSolver is a math solver for engineering and scientific equations.
Compare Maple with alternatives
Compare Wolfram Alpha and Maple and decide which is most suitable for you.