SageMath is described as 'free open-source mathematics software system licensed under the GPL. It combines the power of many existing open-source packages into a common Python-based interface' and is a well-known app in the Education & Reference category. There are more than 50 alternatives to SageMath for a variety of platforms, including Windows, Linux, Mac, the Web and Android. The best alternative is GNU Octave, which is both free and Open Source. Other great apps like SageMath are R (programming language) (Free, Open Source), Jupyter (Free, Open Source), MATLAB (Paid) and Mathematica (Paid).