WowAce

Allows custom-triggered boss mod timers to be created

View party member quest logs

Keeps a list of all items you want and shows how much you need.

SinkLib

Displays a reliable cooldown timer for the Shaman Ascendance ability

KC_Items

SmartyCat

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

PiraPlex

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

A Data Broker plugin to show AddOn memory usage.

Checklist and notes addon.

aX_RaidStatus

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

Expo

Quickly builds /target macros for immediate use.

Plays amusing sounds whenever you skin a mob

Leveling guides for trade skill professions.

ERP

InstanceMaps