requestAnimationFrame.md

// shim layer for requestAnimationFrame with setTimeout fallback
// from http://paulirish.com/2011/requestanimationframe-for-smart-animating/
var requestAnimFrame = (function(){
  return window.requestAnimationFrame       || 
         window.webkitRequestAnimationFrame || 
         window.mozRequestAnimationFrame    || 
         window.oRequestAnimationFrame      || 
         window.msRequestAnimationFrame     || 
         function( callback ){
           window.setTimeout(callback, 1000 / 60);
         };
})();