WowAce

Displays friend notes in unit tooltips, at logon, and in /who results.

Allows customisation of login/logout system messages.

Enables user defined sounds for Party, Guild, Raid and Custom Channel chat messages.

Uses guild notes to add alts' main names to chat windows and other places

Tracks SendAddonMessage Spam

Creates virtual cyphered chat channels over guild addon communication channel.

Shows activity for hidden ChatFrames by making their tabs flash.

Captures chatframe Tradeskill Links for later reference in an easy to read format

Improved Quest Tracker

Desesperated announcing to clearly show the skillings of act inplay.

Generates and posts random Chuck Norris facts to a specified chat medium.

Shows Chat as Combat Text

Allows you to prevent addons from sending and receiving messages.

Don't underestimate your little critters!

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

Allows for easy congratulating when someone earns an achievement.

Displays online friends.

Lists and/or reminds people missing flasks or food buffs at every ready check.

Save and send chat messages to many channels. Allows quick item and profession linking within your messages.

Adds item values to chat messages.