windows nt 4

from The Free On-line Dictionary of Computing (8 July 2008)

Windows NT 4
Cairo

   <operating system> A version of {Microsoft}'s {Windows NT}
   {operating system}, originally code named "Cairo".  It was
   supposed to ship in the first half of 1995.  Details are
   scarce, but it is intended to provide an {object-oriented}
   version of Windows.

   (1996-07-09)