WowAce

Automatic ammo reloading and selection, with warnings.

Target assistance by automatic rewriting of macros

pMutilate

Provides buttons and keybinds for raid flare world markers that never stop working mid-session

Persists collapsed state of headers across wow sessions.

FuBar_GemWatchFu

Provides data about all artifacts in the player's possession.

Bars showing amount of buffstacks

Libary for cleanly inspecting other players

Adds pipes which can control arbitary other statuses (like toggle status on key or "in combat"-state).

ElfReloaded

A fully featured library tracking all ongoing absorb effects

What did you just loot?

Replacement for the default nameplates.

Hotkey interface for spells, macros, other clickables.

GearRating

Puts a timer in /yell when you get Unbound Plague during the Heroic Professor Putricide encounter

Tracks specialization and talent data for group members

DebuffEnough

Adds tier set number and difficulty indicators to tier item tooltips.