WowAce

BadgeWatch

Adds Debuff Highlighting to oUF.

Repairs your items automatically upon visiting a vendor.

Interface for addons to include extra information on the GuildMemberInfo frame.

Overlays Archaology digsite icons on the flightmap

Shift-clicking on a user name in chat shows a tooltip with their whois information.

Reports in raid chat whenever a raid member "fails." /EnsidiaFailsWotLK to configure.

FuBar_IceHudFu

Gives equipped and overall iLvl to indicate the quality of a character's gear.

Simple enhancements to the mission list.

Echos quest objective completion to your party

Displays the remaining time on grid icon's cooldown animation.

Changes the nameplates range and disables clamping to screen

Aiue's Luck Point Handling Addon

A Library for hooking tooltips.

Grid2 LibDataBroker support

A variant of AceGUI's Frame container with an editable input field

Creates parameterized AceGUI-3.0 editboxes with autocompletion

Adds Auctioneer "bought for" filters to Baggins ("disenchant", "vendor", etc)

Frame layout manager for side panels.