bmsterling

Give you the ability to upload files that you have in your Media Library. ?It also let you insert more then one file into a post at a time.
Please submit any bugs or suggested improvements to <a href="https://github.com/bmsterling/Attachment-Extender/issues" rel="nofollow ugc">https://github.com/bmsterling/Attachment-Extender/issues</a>
Need this plugin customized or need a plugin created, contact me via my contact form at <a href="http://kenzomedia.com" rel="nofollow ugc">http://kenzomedia.com</a>
Also available through twitter, @bmsterling
<h3>Credits</h3>
Copyright 2011 Benjamin Sterling
This program is free software; you can redistribute it and/or modify 
it under the terms of the GNU General Public License, version 2, as 
published by the Free Software Foundation.
This program is distributed in the hope that it will be useful, 
but WITHOUT ANY WARRANTY; without even the implied warranty of 
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 
GNU General Public License for more details.
You should have received a copy of the GNU General Public License 
along with this program; if not, write to the Free Software 
Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA

Attachment Extender

Give you the ability to upload files that you have in your Media Library.  It also let you insert more then one file into a post at a time.

Denis Yanchevskiy

DCO Comment Attachment allows your visitors to attach images, videos, audios, documents and other files with their comments. They will also be able to automatically embed links from Youtube, Facebook, Twitter and other services in the comment text.
With plugin settings you can:
<ul>
<li>Limit the maximum file upload size.</li>
<li>Make an attachment required.</li>
<li>Specify whether the attachment will be embedded or displayed as a link.</li>
<li>Enable/Disable autoembed links (like Youtube, Facebook, Twitter, etc.) in the comment text.</li>
<li>Select an attachment image size from thumbnails available in your WordPress install.</li>
<li>Link a thumbnail to a full-size image with lightbox plugins support (see <a href="#faq" rel="nofollow ugc">FAQ</a> for details).</li>
<li>Open a full-size image in a new tab or link thumbnail to the attachment page.</li>
<li>Enable/Disable multiple upload.</li>
<li>Combine images to gallery.</li>
<li>Select an attachment image size for the images gallery.</li>
<li>Restrict attachment file types.</li>
<li>Decide who will be able to upload attachments: all users or only logged users.</li>
<li>Manually moderate comments with attachments.</li>
</ul>
You can also:
<ul>
<li>Add, replace or delete an attachment from a comment on the Edit Comment screen.</li>
<li>Attach an unlimited number of attachments to the comment in the admin panel.</li>
<li>Delete an attachment from a specific comment or bulk delete attachments from comments on the Comments screen.</li>
<li>Display attachments attached to comments to the current post (or a specific post) with the <code>[dco_ca]</code> shortcode. You can also filter by type. See <a href="#faq" rel="nofollow ugc">FAQ</a> for details.</li>
</ul>
Attachments are uploaded to the WordPress Media Library and deleted along with the comment (if this is set in the settings).
REST API is supported.
DCO Comment Attachment is also available on <a href="https://github.com/yadenis/DCO-Comment-Attachment" rel="nofollow ugc">GitHub</a>.

DCO Comment Attachment

Allows your visitors to attach files with their comments

Attachment Extender vs DCO Comment Attachment