WowAce

A library that maintains a cache of items and their types.

FuBar_ExitFu

Simple font replacement

Add in keybindings to place raid marks on mouseover, or the target if there is no unit being moused over

Add-on that shows in a unit tooltip window a number of killed mobs of the same kind

Adds notes to item tooltips

GridAlert

Resizes Blizzard raid frames, and adds additional options.

Automatically and immediately cancels all in-game cinematics and movies

Destruction Warlock priority module for clcInfo -- Maighurl

Allows for gold tracking across multiple time frames

Allows custom-triggered boss mod timers to be created

Sets you to DND when you fight a boss, and some other crap.

Status indicator that shows if a unit is hostile (probably mindcontrolled)

Helps to track outgoing mails

Merchant, gossip and taxi tweaking module for TweakHub.

GraphLib

Helps you see the Halion's Corporeality during phase 3

GameLobby

Replaces the SkadaAbsorbs module with one that acts more like SkadaHealing, but includes shields.