gistfile1.js

var timeAtLastFrame = new Date().getTime();
var idealTimePerFrame = 1000 / 30;
var leftover = 0.0;
var frames = 0;

function runApplication(){
    setInterval(tick, 1000/30);
}

function tick() {

    var timeAtThisFrame = new Date().getTime();
    var timeSinceLastDoLogic = (timeAtThisFrame - timeAtLastFrame) + leftover;
    var catchUpFrameCount = Math.floor(timeSinceLastDoLogic / idealTimePerFrame);

    for(i = 0 ; i < catchUpFrameCount; i++){
        controller.doLogic();
        frames++;
    }

    renderer.renderScene();

    leftover = timeSinceLastDoLogic - (catchUpFrameCount * idealTimePerFrame);
    timeAtLastFrame = timeAtThisFrame;
}

Could update

var timeAtLastFrame = new Date().getTime();
var timeAtThisFrame = new Date().getTime();

to

var timeAtLastFrame = Date.now();
var timeAtThisFrame = Date.now();

It's much faster