Khang Minh

This plugin allows you to highlight code syntax in your posts. It is simple, lightweight, and very easy to use with plenty of options to choose. This plugin works with both editors and won’t mangle your code format. This plugin utilizes the popular PHP syntax highlighting library – <a href="http://qbnz.com/highlighter/" rel="nofollow ugc">GeSHi</a>.
Some Features
<ul>
<li>Load the plugin only when you need it</li>
<li>Option to load media files (CSS, JS, etc.) only when needed</li>
<li>Built-in hooks for easier customization</li>
<li>A lot of options to choose (I bet you don’t need them all!)</li>
<li>Preview any snipplet of code to match your preference</li>
<li>Possibility to add more languages</li>
<li>Parse code within <code><pre></code> tag, <code><code></code> tag or using shortcode</li>
<li>Parse code within comments</li>
<li>Editor button to add code</li>
<li>Two output methods, Table or Ordered list</li>
<li>Style code globally or language-based</li>
<li>WordPress Multi-site compatible (not tested with WPMU)</li>
<li>And more…</li>
</ul>
Get in touch
<ul>
<li>I’m available at <a href="http://betterwp.net" rel="nofollow ugc">BetterWP.net</a> and you can also follow me on <a href="http://twitter.com/0dd0ne0ut" rel="nofollow ugc">Twitter</a>.</li>
<li>Check out <a href="http://feeds.feedburner.com/BetterWPnet" rel="nofollow ugc">latest WordPress Tips and Ideas</a> from BetterWP.net.</li>
</ul>
Languages
<ul>
<li>English (default)</li>
<li>Italian (it_IT) – Thanks to <a href="http://www.polslinux.it" rel="nofollow ugc">Paolo Stivanin</a>!</li>
</ul>
Please <a href="http://betterwp.net/wordpress-tips/create-pot-file-using-poedit/" rel="nofollow ugc">help translate</a> this plugin!
Visit <a href="http://betterwp.net/wordpress-plugins/bwp-syntax/" rel="nofollow ugc">Plugin’s Official Page</a> for more information!

Better WordPress Syntax Highlighter

This plugin allows you to highlight code syntax in your posts. There are plenty of options to choose.

GSaraiva

Create a better display of codes on your page/blog. 
For everybody that publish examples, source-code and some tips about a specific language. 
This plugin do use of GeSHi highlight system, so you will have support for more then 110 languages, including PHP, ASP, Html, JavaScript, CSS, Java, Python, Delphi, C++, C, Visual Basic and much more.
New features:
<ul>
<li>Non-obstructive filter integration.</li>
<li>Syntax highlighting with Style attribute enabled.</li>
<li>Syntax highlighting using AJAX.</li>
<li>Syntax highlighting in RSS 2.0 feeds.</li>
<li>Syntax highlighting with PRE tags .</li>
<li>Syntax highlighting in comments.</li>
<li>Start line number configuration.</li>
<li>Hide toolbar for a code block.</li>
<li>CSS !important to for better style.</li>
<li>New code theme (Summer)</li>
</ul>

Developer Formatter

Create a better display of codes on your page/blog.

Better WordPress Syntax Highlighter vs Developer Formatter