dkukral

Used to add galleries to posts in a WordPress site.
<h3>License</h3>
Copyright 2010 – 2015 Joe Boydston, Don Kukral
This program is free software; you can redistribute it and/or modify 
it under the terms of the GNU General Public License as published by 
the Free Software Foundation; either version 2 of the License, or 
(at your option) any later version.
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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USANone.

Attach Gallery Posts

Plugin for WordPress that allows you to attach a post with a gallery to another post.

johnnyfive

PiwigoMedia WordPress plugin features integration between Piwigo sites and WordPress, using the TinyMCE editor.
The main advantages of PiwigoMedia are:
<ul>
<li>Simplicity. Simple to use and configure</li>
<li>No duplicated media. Images are linked from Piwigo’s site, nothing is imported into WordPress</li>
<li>Independency. WordPress and Piwigo don’t have to be installed on the same server since PiwigoMedia uses Piwigo’s webapi</li>
</ul>

PiwigoMedia

Seems unable to load sites as of WordPress 5.2, just hangs

Doesn't load

This plugins allows media from a Piwigo site to be inserted into WordPress posts and pages.

Attach Gallery Posts vs PiwigoMedia