User interface

Shows you what abilities are available at your class trainer

RCLootCouncil for WoW Classic

Chat addon, filtering messages and UI changes

Addon that puts wowhead BIS guides into the tooltip and provides a window to browse the full list

Better player tooltips - class colors, talents/specialization, GearScore & more - for Classic / TBC / WoTLK

Shared handling of media data (fonts, sounds, textures, ...) between addons.

Give whispers an instant messenger feel.

A main action bar replacement

Battle Pet BreedID displays the BreedID of pets in your journal, in battle, in chat links, and in AH tooltips.

Scan for rare mobs so you can find them and their loot

AddOn development framework

Logging for hardcore deaths, statistics, and widgets

Classic WoW world buff timers and pre buff drop warnings so you never miss a buff.

Increases the debuff size of crowd control effects on the Blizzard raid frames

Combopoints counter

Add-on to help find dungeon requests by sorting thought chat

Displays the sell value of an item when not at a vendor

Tracks rare drops, including companions and mounts

Postal: Enhanced Mailbox support

Build your own combat display — track anything, show anything, share it as a string. Still going on Classic.