WowAce

Collects Herbs, Mines, Gas Clouds, Archaeology, Treasure and Fishing locations and adds them to the worldmap and minimap

Kiwi Plates

Show a texture on demand

Watch tooltip updates to announce when you find specific objects

Library to check whether an item is equipable / appropriate for a given class

Automatically leaves the global channels when inside an instance/raid and restores them when exited.

Displays information about the current zone on the World Map, for WoW MoP Classic

Good old LibTourist-3.0 for WoW Classic Mists of Pandaria

Configure triggers to send messages to your raid team such as timers, rotations, and health/power based triggers. Raid smarter not harder.

Improved Questing Experience

Callback handling Library, normally embedded inside other libraries

Embeddable chat throttling library with traffic shaping and priorities

An intuitive keybindings library.

A library that handles the basics of "window" style frames

Displays information about the current zone on the World Map for WoW Classic Era

Good old LibTourist-3.0 for WoW Classic Era

Display auras on action buttons.

Postal: Enhanced Mailbox support

Reno is a slash-command that can patch predefined options in a macro to change which actions will be chosen.

Mutt (Macro Update Target Tool) provides slash-commands that can patch the predefined targets in your macros.