This is a very crude mass category deletion script for WordPress. I recently inherited a WordPress site with more than 6000 categories. After deleting a ton of old posts, we were left with more than 4000 unused categories, and I needed a way to remove them quickly. Couldn’t find a plugin up to the task, so wrote this. Very crude, but effective. Not a plugin, but a small WP companion script. See instructions in the comment at top of script.