Clearlooks

Primitives that clearlooks special cases:

combobox_button combobox_entry

buttons scale_trough scale_slider

progressbar_trough progressbar_fill

scrollbar_trough scrollbar_stepper scrollbar_slider

entry spinbutton_down spinbutton_up

notebook-tab

menubar menu menu_item

treview_header toolbar

handle resize_grip checkbox radiobutton

Windows

http://msdn.microsoft.com/en-us/library/bb773210(VS.85).aspx

Windows uses approximately 370 "parts" plus their individual states to draw various elements in the operating system.

QT

http://doc.trolltech.com/4.3/qstyleoption.html#OptionType-enum

QT have about 24 primitives used to draw their toolkit.