Allan Collins

This plugin will allow you to add code snippets to your pages/posts. This is great for code tutorial sites.
<h3>Upgrading</h3>
If you are upgrading from version 1.0, you will see an option on the Code Library page that will allow you to upgrade. As a precautionary measure, be sure to back up your database before doing so.

WordPress Code Snippet

This plugin will allow you to add code snippets to your pages/posts.  This is great for code tutorial sites.

WordPress.org

Weston Ruter

George Stephanis

Konstantin Obenland

Mel Choyce-Dwan

This project is adding CodeMirror functionality to the Plugin and Theme file editors, as well as the Customizer Custom CSS box and the Custom HTML widget.
We’re working around discussion on a Core ticket, <a href="https://core.trac.wordpress.org/ticket/12423" rel="nofollow ugc">#12423</a>
Any questions, reach out to #core-customize on WordPress.org Slack or better open an issue on GitHub! See <a href="https://github.com/WordPress/better-code-editing/blob/master/contributing.md" rel="nofollow ugc">contributing</a>.
Development of this plugin is done <a href="https://github.com/WordPress/better-code-editing" rel="nofollow ugc">on GitHub</a>. Pull requests welcome. Please see <a href="https://github.com/WordPress/better-code-editing/issues" rel="nofollow ugc">issues</a> reported there.

Better Code Editing

Adding CodeMirror functionality to the Plugin and Theme file editors, as well as the Customizer Custom CSS box and Custom HTML widget.

WordPress Code Snippet vs Better Code Editing