WowAce

Prints a message in your default chat frame when someone in your group gains an aura.

Building a Better Mailbox

A library to return spell duration and debuff type of a spellID.

Combat log evolved.

Don't underestimate your little critters!

Automates bites during the Blood-Queen Lana'thel encounter in Icecrown Citadel

Gives detailed descriptions of particular localities, as zones or instances, and provides optional TomTom integration.

For Developers (of Addons which uses LibWho-2.0): show queues and queries in realtime

Keeps track of time played and rested XP across your characters.

WhiteboardNG

HiveMind

FuBar_KillMeterFu

fmBuffCheck

Tracks profession specific cooldowns and items across all your characters

A fork of BananaDKP.

Loudmouth

Allows you to browse your clients database

Heads Up Display with Player and Target Info

A jukebox for playing wow embedded music.

Provides information about the player's bodyguard.