WowAce

MainAssist

Rep2 displays a message, which shows how much reputation you gained, and how much is needed until the next standing.

Doublerightclick casting, autolure and sound enhancing

SanityItemCache

Library to help with querying unit talents.

A UI for searching the guild roster.

SwapMagic

Helps you automate selling stuff.

Displays information about the current zone on the World Map

Uses guild notes to add alts' main names to chat windows and other places

Shared handling of media data (fonts, sounds, textures, ...) between addons.

Add-on that allows you to setup and quickly switch between different profiles of your action bars

Add a line to herb tooltips that shows what pigment they produce.

NShakedown

Adds your name to chat messages

View party member quest logs

Creates a broker plugin for all your broker launchers

TradeStop

MountUp

Adds manabars to the sides of Grid frames.