WowAce

Heads Up Display with Player and Target Info

Announces interrupts in the chat

Adds a couple of graph displays to Skada.

Rewrite myBindings. An enhanced key bindings interface.

Friends & Guild Data Broker plugin.

The One-Key-Mount™ — Simple to use, configured with Rock

SacredBuff

Control screenshot format and quality via LDB displays

Tracks profession specific cooldowns and items across all your characters

Instant PROC notification

LilSparky's Workshop mod for Trade Skills

Displays Pet Info for Hunters and Warlocks. Also keeps track of Stables and Pet and Demon skills.

Should I send that recipe to my alt?

Outdated! Please use 'XLoot', available on Curse and WoWI

Note + rep tracking for players, with guild data sharing.

Shows Status Bars that you can drag around and group up for your cooldowns

Keeps track of HoTs, DoTs, Buffs and Cooldowns. With audio and text alerts to refresh them.

Displays the time remaining before your (temporary) pet is dismissed.

Displays how many times you have jumped.

Filters AFK and DND messages after you've seen them once.