WowAce

Point to quest POIs on your minimap

Bayi's Extended Questlog

Keeps track of quests.

Create panels for customizing your UI, sucessor to eePanels

Configurable Castbars

Violation

Target Debuff monitor. Stacking aware, giving current and potential debuff status.

An extension to the default WoW Unit Frames.

Display auras on action buttons.

Show item durability and quality in the character frame.

Textures for Stop Motion

A collection of Rogue modules.

an embeddable library providing an abstraction layer for tracking and querying Blizzard's Nameplate frames with ease and effi...

Display aura information inside action buttons

Marks the locations of Hallow's End candy buckets on the worldmap and minimap.

Try on different gear and see their total stats and their differences. In short, an ingame CT-Profiles-like addon.

Raid Frames using the oUF framework.

MorgDKP

A blizzard group finder replacement

Keeps track of your top hits, heals, criticals, etc.