regen

<p>This plugin inserts quicktags of the admin page to the upper part of textarea of the comment form.</p>
<h4>Features</h4>
<ul>
<li>You can edit tags in the admin page.</li>
<li>You can limit quicktags by user roles.</li>
</ul>


Comment Form Quicktags

This plugin inserts a quicktag toolbar on the comment form.

darrinb

<p>Easily include raw markup languages (HTML, CSS, PHP, etc.) in comments using custom quicktags.  No need to encode, the filter does it for you.  Creates convenient “encode” buttons for comment authors in the HTML editor.</p>
<p>Also adds basic quicktag buttons on the comment forms, using the Quicktag API built into WordPress (as of 3.3).</p>


Comment Form Quicktags vs WP Comment Encode