WowAce

In-game EPGP guild helper, supports standby, main/alt shared pools, minEP, offpecGP. Fixed price list with progress multiplier.

A loot distribution addon meant to improve master looting during raids.

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

Go quick, or go home!

A lib to manage action bar and timers

A simple addon that warns you if your pet isn't attacking while you're in combat.

Adds easier gear switching to FuBar.

JostleLib

Constructs a SimC export string for an item without equipping it

A library to help with localization of Archaeology artifacts

A library that tells wether a item is a quest item or not (equipped or in bags)

A library which provide tools for detecting adverse effects on units.

Opens professions and shows their skill level.

EasyTrack

Capsule

Tells you who bought your auctions.

EnvenomX

Movable frame library.

pMutilate

Denial2