WowAce

Allows you to create icons, which can be customized greatly by user's input. CiR is more than just the usual cooldown tracker.

T_Tracking

InspectFix

Replacement for default bags.

LDB data source for herb, ore and skinning node data

FuBar_TinyPadFu

Taggle

Separate indicator for your HoTs with timer.

Tracking and ranking of dps/hps in a guild.

Simple display and management of Away / AFK / Busy / DND status via broker or minimap

fmBuffCheck

Blacksmithing data for Ackis Recipe List.

Warnings about tanking specific abilities

Reno is a slash-command that can patch predefined options in a macro to change which actions will be chosen.

VersionChecker

Keep your pet fed

Add-on that allows you to setup and quickly switch between different profiles of your action bars

AltClick an item in your bag to add it a mail, auction, or trade frame, and alt-click to buy a stack if reagents.

A library to return spell duration and debuff type of a spellID.

Buffalo2