WowAce

Timer bars with that extra sweetness.

UIFrameFlash to Animation conversion library for Floating Chat Frame functions.

Allows addons to easily create a lightweight minimap icon as an alternative to heavier LDB displays.

Simple AceGUI3 dropdown item classes for font/statusbar/sound/etc.

A library for transmitting and receiving durability information of players in your group.

A library for transmitting and receiving latency information of players.

Shared handling of media data (fonts, sounds, textures, ...) between addons.

Library that handles chat output.

Toss those bugs inna sack.

Grabs bugs for the bug sack.

AddOn development framework

Redirect character errors, system messages and information messages.

Provides the /in command for delayed execution.

A core for your informational plugins to plug into.

Friends & Guild Data Broker plugin.

A total number of quests Data Broker plugin.

Zone text Data Broker plugin.

A FPS Data Broker plugin.

Remaining and rested XP Data Broker plugin.

A data broker plugin showing your longest fight and your current fight time.