WowAce

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

Library providing multi-column tooltips.

Show the appearance of an item when you mouse over it

Set and manage character notes that are displayed in unit tooltips and /who results.

Item stat breakdown, analysis and comparison

Lightweight but powerful auction house interface

Collectinator is an addon which will scan your pets and mounts and provide information on how to obtain them.

Complete tradeskill information.

A fancy LDB reputation display, show faction reputation and reputation change history

Kaliban's Class Loot List Star Display

Simple and super light-weight tracking of profession links for all your alts.

Adds various information based on PeriodicTable to item tooltips.

Shows where the equipment of inspected users or yourself is from.

Displays item durability and repair cost.

Tooltip of awesomeness. Moo. It'll graze your pasture.

Manages social information with a focus on main-alt associations.

Dynamic item DKP calculation

Interacts with TinyTip modules, either integrated or standalone, to provide extra centralized functionality. Required for an ...

Shows mana usage as a percentage in a spells tooltip.

Displays friend notes in unit tooltips, at logon, and in /who results.