Windows 3.0 / 3.1
Windows 3.1x was the first to gain significant development and commercial traction. It combined the 8086, 286, and 386 modes of Windows 2 in to one package. It replaced the MSDOS Executive with a Program Manager and File Manager similar to those in OS/2 1.x.
Have something to share about Windows 3.0 / 3.1? Tell us! Comments on any WinWorld articles are welcome over on WinBoards, WinWorld's discussion forum.