WowAce

Friends & Guild Data Broker plugin.

JasonQuest

EasyDKP

A tool to appraise, estimate, or judge your equipment against the equipment of others.

Gives a score for your kit allowing easy comparison with others, also colour codes kit based on appropriateness for your level.

Tracking and ranking of dps/hps in a guild.

Emerge@Durotan-EU Raid Tracker

Note + rep tracking for players, with guild data sharing.

Meeuuuh

Creates new chats with guild channel functionality

Allows customisation of login/logout system messages.

Angry Raid Points Client

Saves contents of your guild bank and sends/receives updates over the addon channel

HazLoot

TGuildFrame

Bidder for DKP points. Usable as standalone bidder, or with DKP - Manager to manage points.

Loot management tool

Calendar improvements

Uses guild notes to add alts' main names to chat windows and other places

Displays online guild mates.