Really simple to use and extrem lightweigt Code Highlighting with 8 different code highlighting themes. You can highlight your code with or without line numbers. It is based on Lea Verou’s Prism.js. Prism is used on several big websites like the Smashing Magazine, A list Apart, CSS Tricks, SitePoint and Drupal, because it is fast, simple and lightweight.
You can find a demo of the plugin on the plugin homepage: Plugin Homepage
Install and activate the plugin. Select your favorite Highlight Theme on the Options page (Settings => AH Code Highlighter). When you write a new post, click on the Code button, choose the code language and insert your code. Click OK and you’re done.