WowAce

oUF_HealComm

picoFPS

Checks .lua files for excess and/or involuntary global variable access. NOT AN ADDON.

CurseBar

GBS tricks other addons into thinking a guild bank is your personal bank.

Fixes "You aren't in a party." spam in battlegrounds

RaidGnome

AuctionProfit saves information from your invoice auction house mails.

A tiny embeddable library to support the MSP protocol.

A simple broker display that displays in-game and RealID friends in a tooltip.

Provides an interface for querying and caching item levels for targets and party members.

ScrubFork

Adds Debuff Highlighting to oUF.

A very simple addon to whisper LK's Defile targets quickly.

Visual interrupt monitor

Reduces achievement spam when a group of people earn the same achievement.

Adds simple coordinates to minimap frame

TrafficJam

Advanced features for sRaidFrames

RaidMarshal