GNU Octave is described as 'Octave is a computer program for performing numerical computations which is mostly compatible with MATLAB . It is part of the GNU Project. It is free software under the terms of the GNU General Public License' and is a very popular numerical computation software in the education & reference category. There are more than 50 alternatives to GNU Octave for a variety of platforms, including Windows, Linux, Mac, Web-based and Android apps. The best GNU Octave alternative is R (programming language), which is both free and Open Source. Other great apps like GNU Octave are Jupyter, MATLAB, Mathematica and SageMath.