WowAce

Puts a timer in /yell when you get Unbound Plague during the Heroic Professor Putricide encounter

FuBar_CombatTimeFu

An extra set of 11x3 buttons, integrated into the default action bar.

On login, displays changes to your guild since the last time you logged in.

Records mail when visiting the mailbox to make keeping track of mail and expiration dates easy.

Shows a frame to track your debuff on Malygos in phase three.

FelwoodFarmer

Timerbar embeddable library

Shows an arrow to your bite victim during the Blood-Queen Lana'thel encounter in Icecrown Citadel (your raid leader must be r...

mDarkPact

Makes those pesky garrison animations go away.

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

ClassColors

Communicates with guild members for their positions on the world map

Light-weight enhanced casting bars

InventoryLib

Automatic tracking of the current target's creature type. For the discerning PvE hunter.

Raid level alternative player power warning (Atramedes, Cho'gall, Lord Rhyolith)

A Healing Assignment management addon

BankAccountant