WowAce

WindowLib

A standalone addon to walk around the 4.0.1 inspecting BUG. Also provides help for other addon that need Inspecting

Keeps track of instances you are saved to on your characters.

Automagically call who should cross over

Minimalistic group roll frames.

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

Displays the remaining time on grid icon's cooldown animation.

AuctionSort

oUF_Castbar

Adds spell-based range checking to Grid, and the ability to check multiple ranges.

Very very simple tooltip

A lib to manage action bar and timers

A small datatext for ElvUI-using Shamans that gives them accurate info about their Reincarnation cooldown

Manage Raid Queues

Check for flask/food buffs

RBM_BlackTemple

Experimental timer library that uses the Animation system as a scheduler.

TrainingWheels

Show a bar indicating the remaining lifetime of your temporary pet

Object-orientation library