WowAce

Displays additional information for Mythic Keystone dungeons

LibDataBroker-1.1

Makes the default frames moveable via simple drag and drop

Give whispers an instant messenger feel.

Adds spec switching support to individual AceDB-3.0 databases.

Library providing multi-column tooltips.

A library for transmitting and receiving latency information of players.

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

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

The original source for where things are in Pandaria

Show item levels in the character frame

Wowhead Data dump for GatherMate2

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

Library that handles chat output.

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

Replacement for the default UI's StaticPopup dialogs.

Restores access to removed interface options in Legion

Parses ToC and adds About panel to Interface options

Officially the original source for where things are in the Broken Isles, in HandyNotes

Modular casting bar.