TopView (1985) 5 Utility DOS

Released by IBM in 1984, TopView was a text-mode windowed multitasker for the IBM PC, XT, and AT computer. It featured preemptive multitasking, text-based windowed task sessions, overlapping windows, and supports the use of a mouse. In part, it was one of the reasons why overlapping windows were added to Microsoft Windows 2.0. TopView was later overtaken by DesqView, OS/2, and Windows. For more information, see the Topview 1.00 Software Spotlight.

• 1.x

Xenix (1984) 86 Linux

Xenix was the variant of UNIX originally published by Microsoft, later sold to SCO. It added a variety of technical enhancements over System V Unix, including a menu-driven business shell. It was ported to many different platforms from a PDP-11 including the Altos 8600 (First x86 port), IBM PC, Intel System 86, TRS-80 Model 16, SCP Gazelle II, and Apple Lisa. The Xenix Software Development System, Microsoft Multiplan 2.x and Microsoft Multiplan 3.x, Microsoft Word 3.0 and Microsoft Word 5.x, and FoxBase Plus 1.00

• IBM PC 2.00