WowAce

Monitor the remaining duration on your Mysterious Eggs and other perishable items.

Test whether the player can really dispell a buff or debuff, given its talents.

Customizing your buff display

On login, displays changes to your guild since the last time you logged in.

lugMD

Displays the time until the next battle and more.

tekSupport

Allows you to create icons, which can be customized greatly by user's input. CiR is more than just the usual cooldown tracker.

Saves contents of your guild bank and sends/receives updates over the addon channel

Group interrupt cooldown tracking.

Shows your FuBar addons in your LDB display.

SupplyAndDemand

BA3_SpellAbilities

Monitors for friendly deaths and announces them as in Myth: The Fallen Lords

FuBar_NinjutFu

Show extra information about Jewels and Enchants in tooltips.

PetBar

A library to help with localization of Archeology dig sites

Makes those pesky garrison animations go away.

A fully featured library tracking all ongoing absorb effects