How can you animate in OpenGL without using the idle function glutIdleFunc()?

Question

Basically, what is another method for animating besides idle?

Answer 1

Pseudocode

while(!application_end) {
  old_time = time;
  time = get_time();
  update_scene( time - old_time );
  draw_scene();
  flush_output();
  sleep(1); 
}

... and this is the heart of 99.99% serious OpenGL programs...

P.S. glut is not OpenGL, it's an addon library over OpenGL for abstraction over the OS.