WowAce

Replacement for the default UI's StaticPopup dialogs.

Keeps track of group members and keeps an up-to-date cache of their specialization and talents.

Timer bars with that extra sweetness.

Does stuff for sachmo

A library to help with localization of races.

A library to help with localization of bosses.

An intuitive keybindings library.

Embeddable chat throttling library with traffic shaping and priorities

A Replacement for standard UIDropDownMenu

Replacement for ActionButton_Show/HideOverlayGlow APIs

A library to help with localization of the output of UnitCreatureType.

A library to help with localization of factions.

Library of compressed itemid sets.

Provides one or many frames for dumping text into.

A library to provide a markup syntax

A library to provide unit-oriented tags to LibDogTag-3.0

Database of Diminishing return categories and general data

Grabs bugs for the bug sack.

Provides one or many informational windows with optional interactive widgets.

Queing of /who and SendWho() queries and a much better interface (see docs), with gurantee to be executed & callback.