WowAce

Automatically enables or disables combat logging based on location.

AddOn development framework

Tells you the Tiller, what food they like, and if you have fed them today for the quests A Dish for ...

Toss those bugs inna sack.

Adds spec switching support to individual AceDB-3.0 databases.

Scan for rare mobs so you can find them and their loot

Collects, analyzes and presents information about the virtual economy.

Tracks herbs/ore/items that can be broken into component pieces

The original HandyNotes source for where things are in Battle for Azeroth

Smooth combat HUD based on ArcHUD2

Redirect character errors, system messages and information messages.

EBB adds groups of bars to your screen showing you which (de)buffs currently affect your toon or some other units.

From bags we came, to bank we return

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

A library for transmitting and receiving latency information of players.

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

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

UIFrameFlash to Animation conversion library for Floating Chat Frame functions.

Timer bars with that extra sweetness.

Library that handles chat output.