The classes in the libraries can be classified as follows:
Core application skeleton - classes needed by almost every application.
Configuration settings - classes to access KDE's hierarchical configuration database, global settings and application resources.
Keyboard accelerators and shortcuts - classes helping to establish consistent key bindings throughout the desktop.
File and URL handling - temporary files, decoding or URLs, icon loading and manipulating.
Image processing - icon loading and manipulating.
Interprocess communication - subprocesses, DCOP helper classes .
Utility classes - memory management, random numbers, regular expressions, string manipulation, char sets, etc.
Widgets - widgets classes for list views, rulers, color selection, ...
Dialogs - full-featured dialogs for file, color and font selection
Initializes and controls a KDE application.
Makes sure that only one instance of an application can run simultaneously.
Holds information for the about box.