WowAce

Show item levels in the character frame

An intuitive keybindings library.

Tracks rare drops, including companions and mounts

Collects Herbs, Mines, Gas Clouds, Archaeology, Treasure and Fishing locations and adds them to the worldmap and minimap

Modular casting bar.

Replacement for ActionButton_Show/HideOverlayGlow APIs

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

Creates and manages secure Action Buttons

Library to check whether an item is equipable / appropriate for a given class

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

Officially the original source of knowledge of where things are in Draenor during Warlords, in HandyNotes

Does stuff for sachmo

Restores access to removed interface options in Legion

Database of item upgrade IDs

Enables multi-line/unlimited-length pasting of text or commands into WoW

Wowhead Data dump for GatherMate2

Shared handling of alternate identity data between addons.

Arena unit frames

A library to help with localization of in-game subzone names.

Custom widgets for AceGUI-3.0 and AceConfigDialog-3.0.