WowAce

Fires events whenever a raid member "fails".

Displays info about who rolled Need/Greed/Pass on items that are currently rolled for

Monitors AP when dots are applied, clearly showing current vs applied AP levels.

Aperture

Scorchio!

Ingela's Rapture is a lightweight and highly configurable addon that gives you a cooldown bar for the internal cooldown of Ra...

Adds on-screen buttons for the farming tools and seeds.

LDB data source displaying character stats

Display an arrow that points to a raid/party member anchored to raid frames

GemCensus inspects people and records which gems they have socketed. Then displays which gems are the most popular.

SupplyAndDemand

ImprovedTargetFrame

Displays a grid of guild ranks versus permissions.

Smooth combat HUD based on ArcHUD2

VendorSearch adds search features when buying items from any vendor

ItemEnchantApplication

DHUD2

Loudmouth

Makes the message dialog movable

Provides the the health and target of by an unit targeted mob (meant to be used for tanks).