WowAce

Resizes some default UI frames (GuildUI, LootFrame, RaidInfo, TradeSkillUI and TrainerUI) to show more lines

OneBag is a replacement for the default game bags that combines all the bags into one frame.

Fancy up the ExtraActionButton frame

Helps you automate selling stuff.

FuBar_ItemBonusesFu

Monk Brewmaster/WindWalker Priority and Buff/Debuff Tracking Tool

MendWatch

Augmented Virtual Reality. Draw and add markers in the 3d world.

Speeds up triggering actions such as items or spells by triggering them on key/mouse down rather than release

Assister

Good looking, smoothy and helpful nameplates

AceBuffGroups

HunterAEP

FuBar_OutfitterFu

Library supporting plug in filters.

Library to help with querying unit talents.

StatStain

Clean looking square minimap with many options.

Warnings about tanking specific abilities

Assistance to the dance during Dread Spray