Amaury Balmer

WordPress 3.1 and up allow for reasonably simple custom taxonomy, this plugin makes it even simpler, removing the need for you to write any code.
Add support for taxonomy with or without hierarchical. Choose the selector type for write post.
Allow to add taxonomy to any objects registered on your installation. This plugin can be coupled with the plugin ACF to a new term meta database that allow to create on fly any field need for the taxonomy. For example, for a “Number” taxonomy, you can add fields : number ID, date of parution, screenshot, etc !
This plugin is developped on WordPress 3.5, with the constant WP_DEBUG to TRUE.
This plugin allows you to add taxonomy just by giving them a name and somes options in the backend. It then creates the taxonomy for you, takes care of the URL rewrites, provides a widget you can use to display a “taxonomy cloud” or a list of all the stuff in there, and it allows you to show the taxonomy contents at the end of posts and excerpts as well. 
To boot, it comes with a set of template tags for those who don’t mind adapting their own theme.
For full info go the <a href="https://github.com/herewithme/simple-taxonomy" rel="nofollow ugc">Simple Taxonomy</a> page.

Simple Taxonomy

WordPress 3.1 and up allow for reasonably simple custom taxonomy, this plugin makes it even simpler, removing the need for you to write any code.

Paul

Gemini Labs

Pollux allows you to easily add custom Post Types, Taxonomies, Meta Boxes, Global Settings, Archive Page meta, and more…all within mere minutes.
Instead of drag-and-drop, all configuration is added using simple <a href="https://learn-the-web.algonquindesign.ca/topics/markdown-yaml-cheat-sheet/#yaml" rel="nofollow ugc">YAML</a> markup on the Pollux settings page.
Pollux uses the <a href="https://wordpress.org/plugins/meta-box/" rel="ugc">Meta Box</a> plugin to add custom meta-boxes. If the Meta Box plugin is not installed, Pollux will prompt you to do so on the Pollux settings page.
Please see the <a href="https://github.com/pryley/pollux/wiki" rel="nofollow ugc">plugin wiki</a> for complete examples on how to use YAML markup in the plugin. Once you’ve used it, you’ll wonder how you ever managed without it!
Pollux was made to complement themes built on the <a href="https://github.com/pryley/castor-framework" rel="nofollow ugc">Castor framework</a> (i.e. <a href="https://github.com/pryley/castor" rel="nofollow ugc">Castor</a>), but it can be used with any theme.

Pollux

Pollux allows you to easily add custom Post Types, Taxonomies, Meta Boxes, Global Settings, Archive Page meta, and more...all within mere minutes.

Simple Taxonomy vs Pollux