WowAce

Forces LSM and LibSink to use specific textures and sinks.

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

MoBuffs

FuBar_FuzzyClockFu

Used to visualize and change values of variables/variable-trees in game

Adds Raid Target Icon status to Grid (Player or Player Target).

RBM

Color manipulation library.

AltClick an item in your bag to add it a mail, auction, or trade frame, and alt-click to buy a stack if reagents.

QR Code builder library

BossWhisperer

ezIcons

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

A Latency Data Broker plugin.

A module that lets you find out what today's dailies are without having to visit the quest givers.

NextStep

Doodle

EquivalencePoints

Toolset for tanks, providing information on taunts and other valuable information.

Lists and/or reminds people missing flasks or food buffs at every ready check.