Mathematica, MATLAB, Wolfram Alpha, Maple, SMath Studio, GNU Octave, Maxima, SageMath, microMathematics Plus, wxMaxima, WabbitEmu, fxSolver, CADWOLF, Miramath, Julia, TI-Smartview, CompPad, Mathmatiz, Mathics, meta-calculator, Dynamic Math Solver, web2.0calc are some alternatives to MathStudio.