Ben Marshall

Integrate <a href="https://daringfireball.net/projects/markdown/" rel="nofollow ugc">Markdown</a> into WordPress comments with the Parse Markdown plugin. A simple, no configuration-required, standards-driven plugin that allows commenters to use Markdown markup in their comments.
For more information on how it works and how to integrate in other plugins or themes, see the <a href="https://www.benmarshall.me/parse-markdown-wordpress-plugin/" rel="nofollow ugc">Parse Markdown documentation</a>.

Parse Markdown

Integrate Markdown into WordPress. Simple, no configuration-required, standards-driven plugin allowing commenters to use Markdown in their comments.

Terry L.

Generation of diagrams and flowcharts from text in a similar manner as markdown by using <a href="https://mermaid.js.org/" rel="nofollow ugc">mermaid.js</a>
WP Mermaid is smart enough that loads mermaid.js only when your posts contain Mermaid syntax, by detecting the use of shortcode and block. So it will not be loaded on your website everywhere.
= See also
If you are looking for a <a href="https://github.com/terrylinooo/githuber-md" rel="nofollow ugc">Markdown editor</a> supporting Mermaid, you can also check out my WordPress plugin called the <a href="https://wordpress.org/plugins/wp-githuber-md/" rel="ugc">WP Githuber MD</a>, which provides a variety of features not just Mermaid, it is worth to try.
<h3>Translations</h3>
Chinese (zh_TW) by <a href="https://terryl.in/" rel="nofollow ugc">Terry L.</a>. 
Japanese (ja_JP) by <a href="https://colocal.com/" rel="nofollow ugc">Colocal</a>.
<h3>Copyright</h3>
WP Mermaid, Copyright 2020 TerryL.in 
WP Mermaid is distributed under the terms of the GNU GPL
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 3 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.

WP Mermaid

Generation of diagrams and flowcharts from text in a similar manner as markdown by using mermaid.js

Parse Markdown vs WP Mermaid