WowAce

Adds information about the items tokens can purchase and vendor location to tooltip

Exports encounter journal data into XML

A set of datatexts for ElvUI that provide you with detailed info about your professions

What actual item level is an item? Yes, it's horrible we need a library for this.

PaintChipsLib

DKPmon

NiHao

Logs hunter's use of Feign Death

CatFight

Adds PvP status to Grid frames.

Prints combat duration to chat after each fight

Minimalistic LibDataBroker-based guild display

YellCollect

PitBull_Prat

Continously scan for addons using excessive CPU - especially bursts

Advanced features for sRaidFrames

Experience is an addon that helps you evaluate another player's dungeon experience.

Mode7Test

RuinBossTactics

RBM_DrumWatch