WowAce

Mutt (Macro Update Target Tool) provides slash-commands that can patch the predefined targets in your macros.

Tracks skill and tradeskill costs and progressions, as well as trainer locations.

StarVisuals displays various data visualizations

CCBreaker

Collects, analyzes and presents information about the virtual economy.

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

Display an informational fighter jet style HUD while flying or riding

Alternate Rune Display

Quality of Life Tools for Group questing/leveling

Nvp

pDebuffList

Stores a browsable database of spells that mobs cast

BeneCast 10

Cartographer_Trainers

FuBar_TinyPadFu

Cartographer_Routes

Save and load macros.

FuBar_VoiceFu

Displays the zone level ranage of the zone you are in and also gives you a suggest zone and instances to be in.

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