MS-Net

MS-Net, sometimes stylized as MS-NET, was an early network operating system sold by Microsoft during the earliest days of local area networking (LANs). MS-Net was not a complete networking system of its own; Microsoft licensed it to vendors who used it as the basis for server programs that ran on MS-DOS, porting it to their own underlying networking hardware and adding services on top. Version 1.0 was announced on 14 August 1984 and released along with the PC/AT on 2 April 1985. A number of MS-Net products were sold during the late 1980s, before it was replaced by LAN Manager in 1990.

MS-Net's network interface was based on IBM's NetBIOS protocol definition, which allowed it to be ported to different networking systems with relative ease. It did not implement the entire NetBIOS protocol, however, only the small number of features required for the server role. One key feature that was not implemented was NetBIOS's name management routines, a feature 3rd parties often added back in. The system also supplied the program REDIR.EXE, which allowed transparent file access from DOS machines to any MS-Net based server.