Mathematica supports several levels of interfacing to C and C++ programs. You can create "installable" C programs where C functions are directly connected to
Mathematica functions. You can use C to call
Mathematica through
MathLink and get full access to its capabilities. And you can create C program fragments and modify C source code.
.tm — template file for connecting C and
Mathematica functions
CForm — convert an expression to C language form
Splice — splice
Mathematica output into C source files