Mostly Used CDN List

jQuery

<script src="//code.jquery.com/jquery-1.11.0.min.js"></script>

BootStrap

<!--CSS-->
<link href="//maxcdn.bootstrapcdn.com/bootstrap/3.2.0/css/bootstrap.min.css" rel="stylesheet" />
<!--fontsome-->
<link rel="stylesheet" href="//maxcdn.bootstrapcdn.com/font-awesome/4.3.0/css/font-awesome.min.css" />
<!--Scripts-->
<script src="//maxcdn.bootstrapcdn.com/bootstrap/3.2.0/js/bootstrap.min.js"></script>