WowAce

Reduces interface tedium by doing the little things for you.

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

Smart raid loot and DKP tracker with automated standby and learning

Show item durability and quality in the character frame.

A replacement tradeskill window

One large inventory.

Libra

SacredBuff

CombatLog in SimpleCombatlog style

Allows the user to preview and track their progress in the collection of various transmogrification appearance sets

Dynamic item DKP calculation

CraftList2

Adds mob patrol paths to your map.

FlexBar2

A Simple World of Warcraft Spam Filter!

Marks the locations of Midsummer Fire Festival bonfires on the worldmap and minimap.

Does stuff for sachmo

Wowhead Data dump for GatherMate

HUD that you can tweak the way you want.

An extension to the default WoW Unit Frames.