On Commons, it is often required to change lots of files at once. We offer some web-tools for this:

• Help:VisualFileChange.js — Edit lots of files in a category or of one uploader at once
• Help:Cat-a-lot — Categorize a batch of images in a category or search results
• Commons commander — Categorize a batch of images in a category, search results, uploads of one user, new images

Additionally there is

• Commons:AutoWikiBrowser (desktop application)
• User:CommonsDelinker/commands — Rename a category, orphan an image, replace one image with another
• Special:MassMessage — Send a message to many pages or users
• Commons:Bots/Work requests if you can't do it yourself