WindowBlinds was the first full GUI skinning program for Windows. It began development in 1997. And by 2001, thousands of skins/visual styles had been made for it and even influenced the development of Windows XP which includes a quasi-WindowBlindsLite type feature in it to change from classic to "Windows XP style".
This article goes over the history of WindowBlinds complete with screenshots of its evolution. Check it out!
