Marc Tönsing

Ipstenu (Mika Epstein)

This plugin displays the most basic of quicktag buttons on your comment forms, using the Quicktag API built into WordPress (as of 3.3). No jQuery needed.
Contribute on <a href="https://github.com/mtoensing/marctv-quicktags" rel="nofollow ugc">GitHub</a>.

Simple Comment Quicktags

Simple and clean

Make commenting easier with bold, italic, add link and quote buttons on top of the form.

gozerstudio

<a href="https://github.com/doginthehat/postinpost" rel="nofollow ugc">Post In Post</a> provides an interface to import posts in other posts
Requires PHP 5.2 or higher, WordPress 3.3 or higher.
Features:
<ul>
<li>Customisable per post type</li>
<li>Import post content inline or as a shortcode</li>
<li>Import full or excerpt post content</li>
<li>Safety mechanism again infinite nesting of posts.</li>
</ul>

Simple Comment Quicktags vs Post In Post