SMath is a free mathematical program with WYSIWYG editor and complete units of measurements support.SMath was designed to be a free version of PTC Mathcad. It can solve differential equations, graphing functions in two or three dimensions, symbolic calculations including solving systems of equations, matrix operations including determinants, find roots of polynomials and functions, symbolic and numeric differentiation of functions, numeric integration, simple multiline looped programs, user defined functions, and units of measurement.You can also extend SMath with the built-in Extensions Manager tool which allows you to get access to hundreds official and third-party usage examples, plug-ins, SMath Viewer based applications, snippets, interface translations, interactive books, handbooks, and tutorials.SMath is a strong competitor to Mathcad, considering that it's free. Donations are accepted.