DSkinLite is a powerful library to help you develop the user interface program. And we use dskinlite in our current project, so we will optimize it continually. It is a "lite" gui library,and use the xml file to describe how to skin a window. It supports transparent control, change skin's color, change skin at runtime, and also supports pop menu, scrollbar fully. Please visit http://www.uieasy.com/ to get more information about dskinlite.
SkinEngine is a library of components which allows to change visual appearance and behavior of your application with use of the powerful skinning engine and a set of 2000+ ready skins. SkinEngine allow easy skinning your C++, Delphi, VB and .NET application.