WowAce

Keeps track of group members and keeps an up-to-date cache of their specialization and talents.

Postal: Enhanced Mailbox support

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

Database of item upgrade IDs

A library for transmitting and receiving latency information of players.

A library for transmitting and receiving durability information of players in your group.

Library that handles chat output.

Displays additional information for Mythic Keystone dungeons

Chat addon, filtering messages and UI changes

Makes the default frames moveable via simple drag and drop

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

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

Give whispers an instant messenger feel.

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

Tracks rare drops, including companions and mounts

Replacement for the default UI's StaticPopup dialogs.

Parses ToC and adds About panel to Interface options

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

Arena unit frames