WowAce

Shows a bar when your Lifebloom spell is active on a PitBull unit frame.

Displays an estimated time until you're out of mana

SummoningBar

Allows you to set up raid icon markings for all kinds of stuff.

ItemsInEnglish

Adds Yogg-Saron Sanity status to Grid.

SlashConflict

Prints level and time played to chat and takes a screenshot when you ding

Unsolicited

sRaidFrames_QuickHealth

Adds combat feedback to oUF.

Prints the cooldown/GCD on the last spell cast to chat.

A library for sending addon messages over the battle.net chat system

StatBars

Show a bar indicating the unit's power that can change color based on value.

Hides reagent counter on action buttons when you have a glyph that removes reagent requirement.

cyCircled_simpleSphere

CooldownTimers2 extension for extreamly long tradeskill cooldowns

Standalone LibUnitID, with runtime diagnostic utilities

Compliments the colourblind mode "shader" options by making them accessible from the Interface menu.