WowAce

Mutt (Macro Update Target Tool) provides slash-commands that can patch the predefined targets in your macros.

A simple slash-command-based addon for querying item information from the Blizzard servers via ItemIDs and SpellIDs.

Shows skills in a tooltip and allow them to be used. Also keeps track of Cooldowns.

RaidAgent

FuBar_FuXPFu

Need Greed window for EPGP lootdistribution.

GUI Configuration Library

MainAssist

Entertaining kill-shot notification.

Provides database of quest giving npcs/mobs/objects for display on the World Map/Minimap

Track of your tradeskills across characters, create small buttons for them and track cooldowns.

Suppresses chat messages from damage meters and provides single chat-link damage statistics in a popup.

Enchanting data for Ackis Recipe List.

Tracks the precise arrival & departure schedules of boats and Zeppelins around Azeroth and displays them on the Mini-Map and ...

NShakedown

TrackingBar

TouristLib

Displays item durability and repair cost.

FuBar_TrainerFu

RoleCall allows you to easily see the talent specs and roles of everyone in your group.