ReorMadrid

To use it, you must use the [code] shortcode like this:
PHP Code Example:
[easycode] 
< ? php 
e cho “Hi, world!”; 
 ? > 
[/easycode]
In the admin menu, you have options to change the background colors, button colors, language and more.

Easy Code Highlighter

Displays code with syntax highlighting using Prism.js, real line numbering, and a copy button.

Luke Alford

Short code implementation of <a href="https://kazzkiq.github.io/CodeFlask.js/" rel="nofollow ugc">Codeflask</a>
Usage
[codeflask language=”langused” title=”title of file or what ever!”]
code goes here
[/codeflask]
You are required to set both these attributes.
Current attributes
language = type of syntax.
title = title of editor.
Demo
You can view it working on wordpress <a href="http://lukealford.me/portfolio/codeflask-for-wordpress/" rel="nofollow ugc">here</a>

Easy Code Highlighter vs IDE Micro code-editor