WowAce

New/Old BG indicator, Join by ID, Quick Leave Queue, etc.

Tracks SendAddonMessage Spam

YssGuildShop

A small checklist for raid (de)buffs and who brings what.

Prompts for canceling of pet battles if no rare pet is found in the opposing team.

Announces Mage Spells in chat.

XArt

Quest library for mob location and other information

Open inventory items with 1 button

Dynamic item DKP calculation

Threat-2.0

Makes the Blizzard options frame movable and resizable

Friends list improvements: notes, remembering the information of offline friends, friend list syncing and backups, and a fuba...

provides enchanters with a decent tool for managing their profession

A collection of Rogue modules.

Proximo

Check the consumable usage of your raid

BananaBar2

Library to help with querying unit talents.

BuffMe