WowAce

Scan for rare mobs so you can find them and their loot

Chat addon, filtering messages and UI changes

Tracks Raid/Instance/World Boss lockouts for all your characters, daily/weekly quests, currencies, trade cooldowns, and more!

Give whispers an instant messenger feel.

Enables multi-line/unlimited-length pasting of text or commands into WoW

Redirect character errors, system messages and information messages.

Lightweight Chat Improvements

A friendly companion that remembers the chat.

Tracks SendAddonMessage Spam

Adds party/raid role icons in useful places

Shows Chat as Combat Text

A customizable view of friends and guildmates.

Simple display and management of Away / AFK / Busy / DND status via broker or minimap

Displays online friends.

Adds the toon name to the alert that your RealID friend has come online.

Filters AFK and DND messages after you've seen them once.

Allows communication to be shared across realm through Battle.net.

Alert your friends when you ding, get an achivement, or get phat lewts!

A system config addon to WOW

Mage Portal Whisper: whisper custom message when someone asked for a portal but youre busy.