WowAce

Reputation Statistics - Gained, Needed, Rep/Hr, Session Time, etc.

AHsearchNext

Show order resources and troop counts in the Order Hall minimap icon tooltip.

A collection management library similar to .NET's System.Linq

Recount2

LD50_armor

LibJSON-1.0

FuBar_TraxieFu

Shows the Loss of Control spell tooltip

Automatically calls ForecQuit() right before you are AFK-disconnected to quit wow instead of going to the character selection...

Mana regen rate display.

Keeps an eye on someone's distance from you, and alerts you if they get too far.

Object-orientation library

SmartFitter

Shows on the minimap where to fetch Finklestein's reagents

Shows the Guild Achievements Points and Members in the tooltip

LibCooldown-1.0

Shows Jukes and Interrupts

NinjaPoints

obRaidAssist