WowAce

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

BeneCast 10

Reminds you to Life Tap and Dark Pact

Keeps track of people who have recently sent you messages.

Manages the scanning of the auction house in a reliable an efficient manner.

Shows more recipies in the profession window.

ScoreSort

A customizable buff/debuff display replacement for the default Blizzard frames (with right click cancelaura support).

A library to help with localization of Archaeology artifacts

opens/closes all bags when at merchant (instead of only the backpack)

For Developers (of Addons which uses LibWho-2.0): show queues and queries in realtime

Adds custom layouts for Grid

BankItemsFu

TunnelVision

Lexan

Adds a simple percentage threat status to Grid.

Audible Alerts for self-gain, self-lost, any-gain, all-lost of statuses.

Historian

Displays events from Calendar for upcoming week in tooltip.

LDB data source for reputation monitoring.