Add some meta to your terms like tags, categories or custom taxonomies
Very lightweight jQuery script that wraps search terms in an HTML5 mark tag when referer is a search engine or within wp search results.
Add hover text to regular text in posts. Handy for providing explanations of names, terms, phrases, and acronyms mentioned in posts/pages.
Replaces the plain-text category and tag description editor with a visual editor.
Add some tools for taxonomies : Terms suggestion, Mass Edit Terms, Auto link Terms, Ajax Autocompletion, Click Terms, Auto terms, Advanced manage term
Registers taxonomies programtically from a config array and provides other helper functions.
Easier tagging thanks to suggestions from OpenCalais
Adds buttons to select-all / deselect-all terms on taxonomies' metaboxes
Create automatic links to your tags in your posts.
Shows a popup dialog with terms and conditions (EULA) that must be accepted before a file can be downloaded
The plugin allows a user to install a VoIP Call Charges calculator by widget or short-code.
Arrange, re-order, and sort your categories, tags, and other taxonomy terms with a simple drag-and-drop interface.
Export posts, pages, comments, custom fields, categories, tags and more to an export file.
The Rich Text Tags Plugin allows you to edit tag, category, and taxonomy descriptions using WordPress' built in WYSIWYG editor.
Export taxonomies into formatted file compatible with BulkPress plugin.
Allow global terms across all blogs on a multisite installation.
Provides a Search terms cloud widget in the front of your website.
WordPress plugin for integrating with Semantria to generate custom taxonomies. Author's word, "I always strive to make the best than I can
Using the "Single-Term Taxonomies" plugin you can limit the taxonomy terms chosen for a post to maximum one.
Copy or convert terms between taxonomies.
Enhance WordPress media/attachment management
Allows you to easily change the order of different taxonomies/terms/categories.
Create sidebar widgets to display a list of your custom taxonomy terms with ease!
The WPEssence Bulk Categories plugin allows for easily creating multiple categories at once, including slugs and category parents.
Allows to manage and display a glossary in WordPress.
Display a list of taxonomy terms with recent posts in those terms in a simple to use widget
Creates an interactive dictionary of terms and definitions with jQuery and shortcodes.
Creates a 'menu_order' column to specify term order, allowing theme and plugin developers to sort term by menu order.