WowAce

A library allowing for easy creation of graphs

Library that handles chat output.

The original source for where things are in Pandaria

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

Allows you to view all items from all your characters on the same account, when-ever and where-ever you want.

Estimated range display. Type /rangedisplay for config

Give whispers an instant messenger feel.

Database of item upgrade IDs

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

In-game theorycraft. Calculates actual damage/healing based on gear, talents and buffs.

Another HUD addon

Shows the possible loot from the bosses

Replacement for the default UI's StaticPopup dialogs.

Simple Map Mod

Simple and super light-weight tracking of profession links for all your alts.

Modular damage meter.

Parses ToC and adds About panel to Interface options

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

A skinning engine for button-based add-ons.

Addon to manipulate the map