WowAce

Does stuff for sachmo

Alternate Rune Display

GotWood

Embeddable chat throttling library with traffic shaping and priorities

Incubator

Quest library for mob location and other information

EQCompare

Bind spells, items, and macros to keys, without using action buttons

Tracks profession specific cooldowns and items across all your characters

Automatically generate and announce optimal spirit totem assignments during the Gara'jal encounter in Mogu'shan Vaults.

Babble-2.2

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

Show coordinates on minimap

Tweak the tradeskill windows

Configuration for LibToast notifications.

Piece of mind by being one with your class.

Allows for gold tracking across multiple time frames

AceBuffGroups

Various libraries based on LCD4Linux, offering users lower-level UI customizations.

Automagical macros for each talent tier.