Example of calling Guile scheme code from C. The scheme code can be modified without recompiling the C code.

script.scm

(define simple-func
  (lambda ()
    (display "Script called, now I can change this") (newline)))

(define quick-test
  (lambda ()
    (display "Adding another function, can modify without recompilation") 
    (newline)
    (adding-without-recompilation)))

(define adding-without-recompilation
  (lambda ()
    (display "Called this, without recompiling the C code") (newline)))

testguile.c

/*
 * Compile using: 
 * gcc testguile.c \
 * -I/usr/local/Cellar/guile/1.8.8/include \
 * -D_THREAD_SAFE -L/usr/local/Cellar/guile/1.8.8/lib -lguile -lltdl -lgmp -lm -lltdl -o testguile
 */

#include <stdio.h>
#include <libguile.h>

int main(int argc, char** argv) {
    SCM func, func2;
    scm_init_guile();

    scm_c_primitive_load("script.scm");

    func = scm_variable_ref(scm_c_lookup("simple-func"));
    func2 = scm_variable_ref(scm_c_lookup("quick-test"));

    scm_call_0(func);
    scm_call_0(func2);

    return 0;
}