Marcus Downing

Sometimes you want the different sites on a multisite network to share their taxonomies. 
This plugin forces a child site to use its parent’s taxonomies instead of its own.

MU Central Taxonomies

On a multisite network, this makes a child site use the main site's categories and taxonomies instead of its own.

wpexplorer

Post Types Unlimited is an easy way to add custom post types and custom taxonomies to your WordPress site (the right way). The plugin works with any theme and is easily translatable. With Post Types Unlimited you can:
<ul>
<li>Create custom post types.</li>
<li>Create custom taxonomies.</li>
</ul>
Post Types Unlimited makes use of core WordPress functionality for the admin screens and post type, taxonomy registration. This means the plugin is fast, slim and uses the familiar WordPress UI.
Additionally you won’t find any upsell or advertisements in the plugin because there isn’t a “Pro” version. It’s the perfect plugin for adding post types and/or taxonomies to any site (including your client sites) without worrying about extra bloat or annoying ads.
The design of your post types and taxonomies created with the Post Types Unlimited plugin are controlled by your theme. The plugin doesn’t do any hacking or advanced modifications to your templates and thus works great with ANY theme.
If you are using our amazing <a href="https://totalwptheme.com/" rel="nofollow ugc">Total WordPress Theme</a> you will have access to many extra settings that will give you full control over the display of your post types and taxonomies.
This plugin doesn’t have any upsells, banners or other marketing strategies. This makes it perfect for use with any site, including client websites.

Post Types Unlimited

Create unlimited custom post types and custom taxonomies.

MU Central Taxonomies vs Post Types Unlimited