Accurate Javascript setInterval replacement

interval.js

  interval: function (duration, callback){
    var baseline = undefined;
    return {
       run: function() {
         if( baseline === undefined ) {
           baseline = new Date().getTime();
         }
         callback();
         var end = new Date().getTime();
         baseline += duration;
      
         var nextTick = duration - (end - baseline);
         if( nextTick < 0 ) {
           nextTick = 0;
         }
         (function(i) {
             i.timer = setTimeout(function(){
             i.run( end );
           }, nextTick)
         }(this));
       },
       stop: function() {
        clearTimeout( this.timer );
      }
    }
  }

A little more modular for util libs. Also more standardized JS syntax / coding standards.