WowAce

Dropdown library for Ace3 options, extensible to other options formats. Works ok.

Keeps track of healing spells cast by everyone in a group.

Quixote

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

Stitch-1.1

TalentShow-1.0

Various libraries based on LCD4Linux, offering users lower-level UI customizations.

Library handling communcation for Magic* addons

TableTopLib

Good old LibTourist-3.0 for WoW Classic Mists of Pandaria

Keeps track of resurrection spells cast in a group

Helper functions used by my addons, feel free to use them in your addon too

SurfaceLib

Scans your Equipment for cumulative item bonuses and sums them up.

Library supporting plug in filters.

LibRock-1.0

TouristLib

Saves contents of your guild bank and sends/receives updates over the addon channel

Timerbar embeddable library

Library providing mouse-click support for LibQTip-1.0.