WowAce

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

Raid target control and instance shortcuts for Broker

Angry Boss Reminders helps raiders switch to the proper talents, glyphs, and gear for each boss during a raid.

Display an arrow that points to a raid/party member anchored to raid frames

GameLobby

Provides a quick display for the LFG Call to Arms

What did you just loot?

Paparazzi

Dropin replacement library for SetBackDrop

Displays a grid of guild ranks versus permissions.

IDCard

Embeddable chat throttling library with traffic shaping and priorities

Helps you automate selling stuff

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

Enables cooldown notification between players and allows party members access to each-others spell books.

Sneakily inspect how much gold your mouseover target has made so far.

Control screenshot format and quality via LDB displays

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

Adds resurrection, resurrected and soulstone status to Grid2. Uses LibResComm-1.0

Deformat