Kelbooru

Extension Manager

NameDocsDescription

Admin
Recount / Rename / Etc

Feature
Allow users to create groups of images and order them.
Allow users to make comments on images
Show a list of uploaded posts
Allow users to send messages to eachother
A simple wiki, for those who don't want the hugeness of mediawiki

File Handling
Handle MP3 files
Handle JPEG, PNG, GIF, WEBP, etc files
Handle static SVG files.
Handle FLV, MP4, OGV and WEBM video files.
Allows people to replace files for existing posts

General
Edit the alias list
Adds autocomplete to search & tagging.
Turns BBCode into HTML
Lets users use graphical smilies
Allow users to favorite images
Bring a specific image to the users' attentions
Allow users to filter out tags.
Add HTML to some space (News, Ads, etc)
Do things with a random post
Show a random line of text in the subheader space
Show various bits of system information
Allow users to write a bit about themselves

Metadata
Provides several automatic tagging functions
Allow images to have metadata locked
Allow images to have owners assigned to them
Allow users to rate images "safe", "questionable" or "explicit"
Allow posts to have relationships (parent/child).
Tracks & displays how many times a post is viewed
Allows users to mark images as private, which prevents other users from seeing them.
Allow images to have sources assigned to them
Let tags be split into 'categories', like Danbooru's tagging
Add or remove tags to the editor via clicking.
Allow images to have tags assigned to them
Simple artists extension

Moderation
Keep a record of tag changes, and allows you to revert changes.
Simple search and replace