Implicit differential equations software: Systems of partial differential equations, OpenDiscreteDynamicProgrammingTemplate, Plots math surfaces in 3D. C++ source. Free and more.
ODEcalc for Windows: An Ordinary Differential Equation (ODE) Calculator! State your equation and boundary or initial value conditions and it solves your problem. Plots solution y and derivative ydot versus x. Solves most Boundary Value Problems (BVP) and Initial Value Problems (IVP) for Nth order ODE. ODE may be non-linear, implicit, and any order. Source code included ... it's short! Great teaching tool! A Fortran Calculus demo appl.
Fortran Calculus Compiler: Calculus level computer languages are Fortran Calculus and PROSE. Both languages are based on what is called "Automatic Differentiation" (AD). Calculus languages simplify computer coding to an absolute minimum; i.e., a mathematical model, constraints, and the objective function. Minimizing the amount of code allows the user to concentrate on the science or engineering problem at hand and not on the (numerical) process.