Euler (now Euler Mathematical Toolbox or EuMathT) is a free and open-source numerical software package. It contains a matrix language, a graphical notebook style interface, and a plot window. Euler is designed for higher level math such as calculus, optimization, and statistics.The software can handle real, complex and interval numbers, vectors and matrices, it can produce 2D/3D plots, and uses Maxima for symbolic operations.The software is compilable with Windows.