Andrew Parman

This plugin adds a Gutenberg block called <code>IECST Highlighter</code>. After entering a code snippet in the editor, 
the output will be rendered with a syntax highlighting style selected in the IECST Highlighter Settings.
This plugin uses the <a href="https://github.com/PhioAutomation/phio-highlighter" rel="nofollow ugc">Phio Highlighter</a> which is distributed 
with an MIT License, https://highlighter.phioautomation.com/LICENSE.txt.
Development of this plugin is on <a href="https://github.com/PhioAutomation/phio-highlighter" rel="nofollow ugc">Github</a>.

IECST Highlighter

Display beautiful code snippets using the Phio Highlighter for the IEC 61131-3 Structured Text language

zeaks

A simple code snippet plugin for anyone who wants to post any type of code on their site. It’s what I’ve used on Zeaks.org for a while, and highly based off of Danny Van Kooten’s Simple Quote Code Snippets plugin. It’s lightweight, uses no JavaScript, comes with 4 editable color schemes and very easy to use.
Note Does not highlight code, simply displays it in a nice way and allows posting of any code.
Use [code] Your Code [/code] in any post.

Zeaks Snippets

A simple, lightweight code snippet plugin with 4 color schemes that displays code in posts similar to how Wordpress.org does.

IECST Highlighter vs Zeaks Snippets