Extension Manager

Various things to make admins' lives easier
Edit the alias list
Adds autocomplete to search & tagging.
Turns BBCode into HTML
Allow Danbooru apps like Danbooru Uploader for Firefox to communicate with Shimmie
Lets users use graphical smilies
Allow users to favorite images
Allow users to upload archives (zip, etc)
Handle windows icons
Handle MP3 files
Handle JPEG, PNG, GIF, WEBP, etc files
Handle FLV, MP4, OGV and WEBM video files.
Use an additional stylesheet on certain holidays
Allow users to make comments on images
Ban images based on their hash
Show a list of uploaded images
Allow users to rate images "safe", "questionable" or "explicit"
Show various forms of link to each image, for copy & paste
Provides common functions and settings used for media operations.
Annotate images
Allow posts to have relationships (parent/child).
Do things with a random image
Allows admins to rotate images.
A simple wiki, for those who don't want the hugeness of mediawiki
Show various bits of system information
Let tags be split into 'categories', like Danbooru's tagging
Allow images to have tags assigned to them