Jason

No fancy, complicated syntax highlighting here. The goal of this plugin is to allow your bbPress users to post code snippets in their forum topics and replies without having to learn anything new. Basically, any raw HTML/PHP posted within <code><pre></code> or <code><code></code> tags will automatically be converted and displayed in the forum as you’d expect it would.
And additionally, anything posted within <code><pre></code> tags will be automatically escaped from bbPress applying wpautop. This will allow for your forum users’ code snippets to keep their whitespace as they intend.

bbPress Code Snippets

Automatically display HTML/PHP code posted in bbPress topics and replies.

Fredrik Stigsson

This plugin uses <a href="https://github.com/googlearchive/code-prettify" rel="nofollow ugc">Google Code Prettify</a> with customized styling. This plugin uses the default skin, custom styling has been applied to show line numbers and to prevent line-breaks. The wp-code-block is styled by the theme (borders, background color and more), the contents of the pre-block is styled by css in the plugin.

Annytab Code Prettify

A lightweight plugin that automatically prettifies code in [pre] tags, with linenumbers and without line-breaks.

bbPress Code Snippets vs Annytab Code Prettify