WowAce

A library for transmitting and receiving latency information of players.

Toss those bugs inna sack.

Simple and Advanced combined - Bartender4 ActionBar AddOn

Database of item upgrade IDs

Simple AceGUI3 dropdown item classes for font/statusbar/sound/etc.

Library that handles chat output.

Postal: Enhanced Mailbox support

Displays additional information for Mythic Keystone dungeons

Chat addon, filtering messages and UI changes

Replacement for the default UI's StaticPopup dialogs.

Scan for rare mobs so you can find them and their loot

Collects Herbs, Mines, Gas Clouds, Archaeology, Treasure and Fishing locations and adds them to the worldmap and minimap

Parses ToC and adds About panel to Interface options

Makes the default frames moveable via simple drag and drop

Tracks rare drops, including companions and mounts

Tracks Raid/Instance/World Boss lockouts for all your characters, daily/weekly quests, currencies, trade cooldowns, and more!

Afflictions display and cleaning for solo, group and raid with advanced filtering and priority system.

A modular, lightweight and screen-estate saving grid of party/raid unit frames

Restores access to removed interface options in Legion

Give whispers an instant messenger feel.