Win32s

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

Win32s

   <operating system> A free extension for {Microsoft Windows},
   released by {Microsoft}.  Win32s is a software layer on top of
   Windows which allows {32-bit applications} (e.g. {Mosaic}) to
   run on Windows.  Both stand-alone Windows and {Windows for
   Workgroups} run as 16 bit, and both can use Win32s to run
   32-bit applications.

   (1996-07-08)