WordPress.org

I) Features:

• Syntax highlighting for many languages.
• Stability, performance and security inherited from GeSHi.
• Line numbering (optional). Code-number displacements never occur. Numbers are not copied in most browsers.
• Simple usage.
• Per-block styles: each code block on a single web page can be designed on its own.
• Clean, small and valid HTML output.
• Minimal waste of CPU cycles when there is nothing to highlight.
• Clean and well-documented source code.

WP-GeSHi-Highlight is a largely rewritten version of WP-Syntax. Compared to WP-Syntax, WP-GeSHi-Highlight

• creates valid HTML when line numbering is activated (via GeSHi's GESHI_HEADER_PRE_VALID setting).
• creates less HTML source code.
• delivers an improved default style sheet.
• has more styling flexibility.
• has the cleaner source code.
• makes usage of up-to-date WordPress API calls.

II) Usage: Bear in mind: don't use the visual post editor. Then, it is very simple. Insert code blocks like this:

<pre lang="languagestring">
    CODE
</pre>

A short example:

<pre lang="bash">
    $ dd if=/dev/zero of=image.ext3 bs=1M count=10000 oflag=append conv=notrunc
</pre>

All available options are listed and explained on the plugin's website.

III) How does it look in action?

Examples can be found on the plugin's homepage.

IV) Issues:

Let me know if you find one: write a mail or leave a comment.