WowAce

adds navigation buttons to Encounter Journal

Splut

LCDs for WoW

Library to help with querying unit talents.

A UI for searching the guild roster.

In-game EPGP guild helper, supports standby, main/alt shared pools, minEP, offpecGP. Fixed price list with progress multiplier.

Prompts for canceling of pet battles if no rare pet is found in the opposing team.

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

Add item levels to Inventorian

AnyFont

Collects, analyzes and presents information about the virtual economy.

FuBar_AmmoFu

Dynamically atering layout in raid environment (Tanks, Ranged / Melee DPS, Healers)

ColaLight

Adds resurrection, resurrected and soulstone status to Grid2. Uses LibResComm-1.0

aX_RaidStatus

NextStep

Helps you automate selling stuff.

Draws some lovely 3D portraits in the standard Blizzard artwork.

Gathers statistics on certain chance-on-use spells, also known as procs.