WowAce

Arena unit frames

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

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

Library to check whether an item is equipable / appropriate for a given class

The original source for where things are in Pandaria

Ackis Recipe List is an addon which will scan your trade skills and provide information on how to obtain recipes. It works fo...

"Debug" code free since '93!

Replacement for ActionButton_Show/HideOverlayGlow APIs

Give whispers an instant messenger feel.

An intuitive keybindings library.

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

Creates and manages secure Action Buttons

Allows you to view all items from all your characters on the same account, when-ever and where-ever you want.

Myslot is for transferring settings between accounts. Feedback [email protected]

Another HUD addon

Officially the original source of knowledge of where things are in Draenor during Warlords, in HandyNotes

In-game theorycraft. Calculates actual damage/healing based on gear, talents and buffs.

A skinning engine for button-based add-ons.

Shows the possible loot from the bosses

A library to help with localization of the output of UnitCreatureType.