Pacific Tech Graphing Calculator

Graphing Calculator is a tool for visualizing math. It can do arithmetic, algebra, and calculus, and graph equations in two and three dimensions. Graph explicit functions, implicit relations, parametric curves and surfaces, inequalities, points, vectors, contour plots, density plots, color maps, vector fields, ordinary differential equations, surfaces of revolution, coordinate transformations, conformal maps and complex-valued curves, surfaces, and ODEs. Use rectangular, polar, cylindrical, or spherical coordinates. Solve equations numerically, graphically, or symbolically.

"Graphing Calculator is one of the best examples of elegant power and clean user interface of any application I've seen." - Bruce Horn, creator of the Macintosh Finder.