acutesoftware

<textarea name="my-xml-editor" data-editor="xml" rows="15"></textarea>
...
<textarea name="my-markdown-editor" data-editor="markdown" rows="15"></textarea>
...

<script src="//d1n0x3qji82z53.cloudfront.net/src-min-noconflict/ace.js"></script>
<script>
    // Hook up ACE editor to all textareas with data-editor attribute
    $(function () {