[WordPress] An example of cleanly organizing the front end of a custom meta box tabbed interface.

1-custom-meta-box-tabs.php

<div id="acme-navigation">
	<h2 class="nav-tab-wrapper current">
		<a class="nav-tab nav-tab-active" href="javascript:;">Extended Description</a>
		<a class="nav-tab" href="javascript:;">Related Files</a>
		<a class="nav-tab" href="javascript:;">Similar Posts</a>
	</h2>
</div>

<?php include_once( 'partials/extended-description.php' ); ?>
<?php include_once( 'partials/related-files.php' ); ?>
<?php include_once( 'partials/similar-posts.php' ); ?>

<div id="custom-meta-box-nonce" class="hidden">
  <?php echo wp_create_nonce( 'acme-custom-meta-box-nonce' ); ?>
</span>

2-extended-description-nonce.php

<div id="acme-extended-description" class="meta-options">
	<label for="acme-extended-description-field">
		Extended Description
	</label>
	<textarea name="acme-extended-description-field" id="acme-extended-description-field">
		<?php get_post_meta( $post->ID, 'acme_extended_description_field', true ); ?>
	</textarea>
</div>