WowAce

Shift-clicking on a user name in chat shows a tooltip with their whois information.

A Healing Assignment management addon

Add in keybindings to place raid marks on mouseover, or the target if there is no unit being moused over

A simple range indicator for optimizing Halo damage.

FuBar_MiniPerfsFu

Go quick, or go home!

Provides training reminders to help decipher the Blizzard Spell Alerts.

Mob respawn timers

NRT_EPGP

Status indicator that shows the remaining of value of Powerword shield.

Generate a macro with random mounts

A PitBull4 module which shows an arrow that points to raid members

A simple, zero config, trash item seller

Displays events from Calendar for upcoming week in tooltip.

Add lines to ore and gem tooltips that show prospecting sources/results.

Meeuuuh

Warnings about tanking specific abilities

An extra set of 11x3 buttons, integrated into the default action bar.

Color manipulation library.

TwiCo