Nanbooru

Extension Manager

NameDocsDescription

Admin
Use an additional stylesheet on certain holidays
Recount / Rename / Etc

Feature
Rough forum extension
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

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

General
Edit the alias list
Turns BBCode into HTML
Allow users to favorite images
Bring a specific image to the users' attentions
Add HTML to some space (News, Ads, etc)
Do things with a random post
Show various bits of system information

Integration
Sitemap with caching & advanced priorities

Metadata
Allow images to have metadata locked
Annotate images
Allow images to have owners assigned to them
Allow posts to have relationships (parent/child).
Allow users to score images
Tracks & displays how many times a post is viewed
Allow images to have sources assigned to them
Let tags be split into 'categories', like Danbooru's tagging
Allow images to have tags assigned to them

Moderation
Adds an approval step to the upload/import process.
Provides query and selection-based bulk action support
Report posts as dupes/illegal/etc
Keep a record of source changes, and allows you to revert changes.
Keep a record of tag changes, and allows you to revert changes.