WowAce

Out of Mana bar.

Praise the Sun! \[T]/

UIThing

Provides data about all artifacts in the player's possession.

FuBar_PetFu

LDB data source for reputation monitoring.

Warnings about tanking specific abilities

Dailies Quest Tracker

Protractor

Count and Track Daily Quests

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

EnvenomX

LD50_abar

Collects and displays census information. This AddOn is licenced under the GNU GPL, see GPL.txt for details.

Display who crossed the charges on Thaddius

Keeps a list of all items you want and shows how much you need.

Denial2

Bars showing amount of buffstacks

Eliminates the spam from the chatframe and sums it up in a broker plugin.

Compact scrolling vendor frame