For editing plugin or theme source code files, WordPress natively uses a bland ol' textarea.
The 'Developer Code Editor' plugin uses the advanced CodeMirror JS-based code editor to stylize that textarea and add several improvements to it.
These improvements include syntax highlighting and line numbers, for easily finding code sections and syntax errors.
Unpack and upload it to the /wp-content/plugins/ directory.
Activate the plugin through the 'Plugins' menu in WordPress.
· WordPress 2.9 or higher
What's New in This Release: [ read full changelog ]
· Fixed more minor bugs.