WowAce

LibDataBroker plugin showing some random XP related data

Should I send that recipe to my alt?

A library to help with localization of Archeology dig sites

FruityLoots

FuBar_NavigatorFu

Displays a variety of useful stats for tanking

LibRock-1.0

RapidCast

Shows Chat as Combat Text

For Developers (of Addons which uses LibWho-2.0): show queues and queries in realtime

A fully featured library tracking all ongoing absorb effects

Right-click on minimap blips to open a targeting menu (out of combat).

Draws some lovely 3D portraits in the standard Blizzard artwork.

Allows frames to be dragged around, without permanently changing their position.

kgPanelsConfig

Saves contents of your guild bank and sends/receives updates over the addon channel

FuBar_GemWatchFu

Library for tracking cooldowns of other players

InventoryLib

Splut