WowAce

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

Displays an alert whenever you loot an item for the first time.

Creates virtual cyphered chat channels over guild addon communication channel.

Sphere

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

Instant PROC notification

Cartographer_Routes

Customizing your buff display

Provides information of tradeskill and crafting materials that are in the banks and bags of your characters.

Visual loot monitor

Good looking, smoothy and helpful nameplates

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

Cancellation

Displays online friends.

Powerleveling guide framework

DeclineDuel

FuBar_WindFuryFu

Square Minimap and more

You've got mail!

Library to help with querying unit talents.