title: How is setTimeout implemented in the javascript interpreters or timers in general?
body: <p>How is a function called after a time has passed implemented in javascript or any other interpreted language?</p>
  
  <p>In other words, is there a loop behind in the javascript interpreter that checks all the time a list of timers, or is there any particular way that the operating systems handle this?</p>
  
  <p>Thanks</p>