In browser ace editor. - Paste the whole tag in the url bar and press enter - Bookmark the page - Profit!!

gistfile1.txt

data:text/html, <style type="text/css">#e{position:absolute;top:0;right:0;bottom:0;left:0;font-size:14px}</style><div id="e"></div><script src="http://d1n0x3qji82z53.cloudfront.net/src-min-noconflict/ace.js" type="text/javascript" charset="utf-8"></script><script>var e=ace.edit("e");e.setTheme("ace/theme/monokai");e.getSession().setMode("ace/mode/php");</script>