Enrico Sorcinelli

Taxonomies Sortable allow to sort non-hierarchical taxonomy terms associated to objects by drag&drop them on the administration interface.
<h3>Usage</h3>
Once the plugin is installed you can make a taxonomy sortable in the following ways:
<ul>
<li>Programmatically by adding <code>'sortable' => true</code> argument in <code>register_taxonomy()</code>.</li>
<li>Programmatically by using <code>taxonomies_sortable</code> filter below.</li>
<li>Using the Settings->Taxonomies Sortable administration screen by selecting non-hierarchical taxonomies you want to make sortable.</li>
</ul>
Note that making a taxonomy sortable, implicitly means also setting <code>sort => true</code> for that taxonomy.
<h3>Hooks</h3>
<code>taxonomies_sortable</code>
Filter allowing to programmatically set sortable taxonomies.
<pre><code>apply_filters( 'taxonomies_sortable', array $taxonomies )
</code></pre>
<code>taxonomies_sortable_admin_settings</code>
Filter allowing to display or not the plugin settings page in the administration.
<pre><code>apply_filters( 'taxonomies_sortable_admin_settings', boolean $display )
</code></pre>

Taxonomies Sortable

Allows to sort taxonomy terms associated to objects.

Ben Huson

<blockquote>
This plugin in only required for versions prior to WordPress 3.5 
 I am no longer continuing to provide support for this plugin. If anyone would like to take over commit access please contact me via the details in my profile.
</blockquote>
This plugin collapses and reduces the height of hierarchical category and taxonomy panels in the WordPress admin.
It always bugged me that when editing a post the categories panel took up so much height if you only had a few categories. This was also the same for custom hierarchical taxonomies.
This plugin just adds a couple of styles to your admin to override this and collapse that space.
I created an initial patch for this which, with contributions from other WordPress developers, was included in WordPress 3.5. You can <a href="https://core.trac.wordpress.org/ticket/15925" rel="nofollow ugc">see the patch here…</a>

Compact Taxonomy Checkboxes

Collapse and reduce the height of hierarchical category and taxonomy panels in the WordPress admin (not needed for WordPress 3.5+).

Taxonomies Sortable vs Compact Taxonomy Checkboxes