KJS

KSJEmbed provides a method for binding JavaScript objects to QObjects,
so you can script your applications.

KMediaPlayer builds on the KParts framework to provide a common interface for
KParts that can play media files.

KNotifyConfig provides a configuration dialog for desktop notifications which
can be embedded in your application.

A library that provides access to all contacts and the people who hold them.

KPlotting

Kross

libalkimia is a library with common classes and functionality used by finance
applications for the KDE SC.

This library provides a Qt implementation of the DBusMenu protocol.

The DBusMenu protocol makes it possible for applications to export and import
their menus over DBus. Qt5 library