WowAce

A customizable view of friends and guildmates.

lern2count adds ABinfo castcounts to spell and actions. It has a builtin reagentcount too.

CBRipoff

A simplistic clock.

A library to return spell duration and debuff type of a spellID.

Replacement for default bags.

World of Warcraft Classic addon to display current zone information.

RaidInfo

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

Buffalo

Gives a score for your kit allowing easy comparison with others, also colour codes kit based on appropriateness for your level.

Prints a message in your default chat frame when someone in your group gains an aura.

RoleCall allows you to easily see the talent specs and roles of everyone in your group.

Tracks the precise arrival & departure schedules of boats and Zeppelins around Azeroth and displays them on the Mini-Map and ...

tekSupport

Loudmouth

A library to help with localization of talent trees.

Configuration library

Monitors for friendly deaths and announces them as in Myth: The Fallen Lords

AltClick an item in your bag to add it a mail, auction, or trade frame, and alt-click to buy a stack if reagents.