WowAce

CharScanner scans Basic Character Data, Talent Specifications, Equipment, PvE/PvP Achievements, PvE Boss Kill Statistics and ...

DHUD2

Tracks whispers and conversations

ShadowGreenLight helps you decide if recasting SWP/Corruption is worthwhile

Keeps track of resurrection spells cast in a group

Addon management panel extreme release edition

API for AceConfig-3.0

Quest helping: fetching items to use, that sort of thing.

GatherHud for GatherMate2 with Routes support

Tracks Black Market Auction House auctions.

Don't underestimate your little critters!

Cartographer_Mailboxes

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

Lets you drag UI frames around

Rewrite myBindings. An enhanced key bindings interface.

Add TomTom Waypoints for Flight Masters in classic

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

Keeps track of time played and rested XP across your characters.

Crowd-control monitor

TradeStop