WowAce

Keeps track of HoTs, DoTs, Buffs and Cooldowns. With audio and text alerts to refresh them.

Find five Ephemeral Crystals, get a pink hippogryph

Shows skills in a tooltip and allows them to be used.

Regain that wasted space!

Checks your gear before bosses and yells at you if you're an idiot

QuestLog

A library to help with localization of item types and subtypes.

SRA

Omnibus

Allows the user to preview and track their progress in the collection of various transmogrification appearance sets

Shows skills in a tooltip and allow them to be used. Also keeps track of Cooldowns.

Improved Questing Experience

Keeps track of current money and all your characters on one realm.

ArcHUD2

View an image of your guild vault from anywhere.

Configure triggers to send messages to your raid team such as timers, rotations, and health/power based triggers. Raid smarter not harder.

Keeps track of space left in your bags.

HUD that you can tweak the way you want.

Show vignette icons sooner

Creates simple table controls for tabular text data.