Ben Huson

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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.
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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+).

Mosterd3d

This plugin contains DD Switch, just a UI plugin for the admin panel. This plugin changes all checkboxes into css3 switches. When a user changes his admin scheme, the switch will change too. It’s just nice for the eye.
<h3>Arbitrary section 1</h3>

DD Switch

Just another DD UI. Change all checkboxes in the admin panel to switches.

Compact Taxonomy Checkboxes vs DD Switch