<p>How does Stackoverflow implement the resizable textarea?</p>

<p>Is that something they rolled themselves or is it a publicly available component that I can easily attach to textareas on my sites?  </p>

<p>I found this question and it doesn't quite do what I want.</p>

<p><a href="https://stackoverflow.com/questions/7477/autosizing-textarea">autosizing-textarea</a></p>

<p>That talks more about automatically resizing textareas whereas I want the little grab-area that you can drag up and down.</p>

At first I believed it was a built-in feature of the
Wysiwym Markdown editor
, but Shog9 is correct: it's not baked-in at all, but is courtesy of the jQuery plugin TextAreaResizer (I was lead astray by the browser was using to check on the
editor demo
because Google Chrome itself adds the expandable functionality on textareas—much like the Safari browser does).