WowAce

Uses guild notes to add alts' main names to chat windows and other places

FuBar_tTracker

Allows customisation of login/logout system messages.

Reverse Engineering will drill down and search your tradeskills for their elements

Cancellation

Shows who controls Wintergrasp and the time until the next battle.

FuBar_OutfitterFu

Gives a Smoother Quest Experience

Makes those pesky garrison animations go away.

A library to handle rearrangement of blizzard's frames when bars are added to the sides of the screen.

FuBar_VolumeFu

A library to return spell duration and debuff type of a spellID.

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

Shared handling of media data (fonts, sounds, textures, ...) between addons.

Calculates incoming damage avoidance and mitigation

Monitors the combatlog identifying players from the oposite faction near you.

A simple data broker display for current Artifact Power

TrainingWheels

One-click smart mounting.

Check the quality of wild battle pets