With jQuery.qrcode.js you can easily add qrcode to your webpages. It is standalone, no external services which go on and off, or add latency while loading. It is based on a library which build qrcode in various language. jQuery.qrcode.js wraps it to make it easy to include in your own code.
Show, dont tell, here is a demo
First include it in your webpage with the usual script tag
<script type="text/javascript" src="jquery.qrcode.min.js"></script>
Then create a DOM element which gonna contains the generated qrcode image. Lets say a div
<div id="qrcode"></div>
Then you add the qrcode in this container by
jQuery('#qrcode').qrcode("this plugin is great");
This is it. see it live.
MicroEvent.js is available on github here under MIT license. If you hit bugs, fill issues on github. Feel free to fork, modify and have fun with it :)