WowAce

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

Simple money display for LDB

Library to help with querying unit talents.

A Data Broker add-on for quickly switching your specialization with gear set and loot specialization.

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

Prompts for canceling of pet battles if no rare pet is found in the opposing team.

SVG Render-bender

Provides information about the player's bodyguard.

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

wRlog

Instant PROC notification

Allows combined aura detection. motw + gotw, all 4 mage int buffs, etc. in one status.

Good old LibTourist-3.0 for WoW Classic Era

Allows for easy congratulating when someone earns an achievement.

QR Code builder library

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

Generate a macro with random mounts

NabuFiveSec

MessageEvent

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