by XoYo Software #Calculation component is a powerful calculation engine for your applications. This component integrates expression parsing and evaluating. It's suitable for heavy-duty number crunching.
by Paseosoft VisualPaseo is a free add-on for Visual Studio : model your xml scripts graphically, using 35 .Net components (incl. current constraints between steps, implicit variables, intuitive configuration, recovery mode) & use them directly in VS (Paseo SDK)
by Farid ABAZIZ A multipurpose software calculator, compute complex arithmetic expressions including matrices and user defined variables, Plot 2D 3D animated functions and is provided with a high level programming language.