How to Display and Format Code Snippets on WordPress ?

What I use is Pretty print, and it’s very simple to setup.

1. Include this script in your header run_prettify.js

2. Start your code with the pre tag

<pre class="prettyprint">
class Voila {
public:
  // Voila
  static const string VOILA = "Voila";

  // will not interfere with embedded tags.
}
</pre>

More information at https://github.com/google/code-prettify