JavaScript Library Performance Penalty

Just checked out a deck by Nicholas C Zakas. He shares his insight in making modern web pages load fast. Apparently this is not rocket science. These days a lot of JavaScript library code is downloaded before the page finishes loading. Not all of that code is required up front. You should just download what you absolutely need on page load. Then grab other JavaScript library code on demand. Why didn't I think of that LOL?

Luckily I do not depend on heavy JavaScript libraries in my own code. Heck. I sometimes don't even use jQuery. Yes that is a recipe for pain. But sometimes you got to roll with just your own code. Makes for a quick page load time. You are in full control.