With CKEditor CodeSnippet module you can insert code snippets with syntax highlighting into the editor.
Syntax highlighting for <?php ?> and <code></code> tags. Drupal.org uses this.
A package for Drupal snippets, autocomplete support, and info file syntax highlighting for Sublime Text.
* This series goes through helpful packages for Drupal (and web development overall). *
This tutorial shows how to install and configure two syntax highlighters. One client and one server side.