WowAce

Blocks Chinese Chat

Displays information about the current zone on the World Map, for WoW TBC Classic

Library for tracking cooldowns of other players

Handles the assignment, coordination, and announcement of many parts of the Lich King encounter in Icecrown Citadel.

Shows activity for hidden ChatFrames by making their tabs flash.

Saves contents of your guild bank and sends/receives updates over the addon channel

Loot management tool

Displays the time until the next battle and more.

Shows current/dot cast haste values

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

A Data Broker add-on for quickly switching your specialization with gear set and loot specialization.

PiraPlex

KivinSpamGuard

Vengeance module for Broker displays.

GirlFriend

Draws some lovely 3D portraits in the standard Blizzard artwork.

FuBar_CRDelayFu

MessageEvent

Open those clams (and other containers)

ChatAssist2